Multiple choice: Which quantity is a vector?
A) Speed
B) Distance
C) Work
D) Velocity
Correct answer: D) Velocity
Explanation: A vector has magnitude and direction; velocity includes direction while speed does not.

 

Short answer: State Newton’s first law of motion in clear words.
Correct answer: An object remains at rest or moves in a straight line at constant speed unless a net external force acts on it.
Explanation: Without a net external force, acceleration is zero.

 

Fill in: Displacement can be negative because it includes ____ .
Correct answer: direction
Explanation: Displacement is a vector quantity, and the sign indicates direction.

 

True or False: Average speed can never be less than the magnitude of average velocity for the same trip.
Correct answer: False.
Explanation: Average speed uses total distance, while average velocity uses displacement; displacement can be smaller than distance or even zero.

 

Multiple choice: The slope of a position versus time graph equals:
A) Acceleration
B) Velocity
C) Force
D) Power
Correct answer: B) Velocity
Explanation: Slope is rate of change of position with time.

 

Short answer: Define acceleration.
Correct answer: Acceleration is the rate of change of velocity with respect to time.
Explanation: A change in speed, direction, or both indicates acceleration.

 

Fill in: For constant acceleration, the area under the acceleration versus time graph equals the change in ____ .
Correct answer: velocity
Explanation: The integral of acceleration over time gives the change in velocity.

 

True or False: In free fall near the surface of Earth, all objects have the same acceleration when air resistance is negligible.
Correct answer: True.
Explanation: The gravitational acceleration is approximately 9.8 meters per second squared for all masses.

 

Multiple choice: Which statement about mass and weight is correct?
A) Mass depends on location, weight does not
B) Weight depends on location, mass does not
C) Both mass and weight depend on location
D) Neither depends on location
Correct answer: B) Weight depends on location, mass does not
Explanation: Weight equals mass times local gravitational field strength.

 

Short answer: State Newton’s third law using two interacting bodies.
Correct answer: When body A exerts a force on body B, body B exerts an equal magnitude and opposite direction force on body A.
Explanation: Action and reaction forces act on different bodies.

 

Fill in: The net force on an object equals its mass multiplied by ____ .
Correct answer: acceleration
Explanation: Newton’s second law states net force equals mass times acceleration.

 

True or False: Kinetic friction is usually greater than static friction for the same surfaces.
Correct answer: False.
Explanation: Static friction maximum is usually larger; once sliding, kinetic friction is lower.

 

Multiple choice: Work done by a constant force that is parallel to displacement equals:
A) Force times displacement
B) Force times displacement times sine of the angle
C) Force times displacement times cosine of the angle
D) Zero for any parallel force
Correct answer: A) Force times displacement
Explanation: When the force is parallel, the angle is zero and cosine is one.

 

Short answer: Define kinetic energy.
Correct answer: Kinetic energy is the energy an object has because of its motion, equal to one half the mass times the speed squared.
Explanation: It depends on mass and speed.

 

Fill in: The change in kinetic energy equals the net ____ done on an object.
Correct answer: work
Explanation: The work–energy theorem relates net work to change in kinetic energy.

 

True or False: Power is the rate at which work is done.
Correct answer: True.
Explanation: Power equals work divided by time.

 

Multiple choice: A block slides down a frictionless incline. Which statement is correct as it moves?
A) Potential energy increases and kinetic energy decreases
B) Potential energy decreases and kinetic energy increases
C) Both energies increase
D) Both energies decrease
Correct answer: B) Potential energy decreases and kinetic energy increases
Explanation: Gravitational potential energy converts into kinetic energy.

 

Short answer: Define conservation of mechanical energy for a system with no nonconservative forces.
Correct answer: The sum of kinetic energy and potential energy remains constant if only conservative forces do work.
Explanation: Energy transforms between forms but total mechanical energy stays the same.

 

Fill in: Impulse equals force multiplied by time and equals the change in ____ .
Correct answer: momentum
Explanation: Impulse–momentum theorem states impulse equals change in momentum.

 

True or False: In an isolated system, total linear momentum is conserved during a collision.
Correct answer: True.
Explanation: With no external net force, total momentum remains constant.

 

Multiple choice: In a perfectly inelastic collision in one dimension, which quantity is conserved?
A) Kinetic energy only
B) Momentum only
C) Both kinetic energy and momentum
D) Neither kinetic energy nor momentum
Correct answer: B) Momentum only
Explanation: Kinetic energy decreases, but momentum is conserved.

 

Short answer: Define center of mass for a system of particles.
Correct answer: The center of mass is the weighted average position of all mass in the system, where the weights are the individual masses.
Explanation: It is the point that moves as if all mass and external forces were applied there.

 

Fill in: Torque equals the product of lever arm length and the component of force ____ to the lever arm.
Correct answer: perpendicular
Explanation: Only the perpendicular component produces rotation.

 

True or False: An object in static equilibrium must have zero net force but can have nonzero net torque.
Correct answer: False.
Explanation: Static equilibrium requires both net force and net torque to be zero.

 

Multiple choice: The moment of inertia of a rigid body depends on:
A) Total mass only
B) Shape and how mass is distributed relative to the axis
C) Speed of rotation only
D) The material but not its distribution
Correct answer: B) Shape and how mass is distributed relative to the axis
Explanation: Farther mass from the axis increases rotational inertia.

 

Short answer: State the rotational work–energy relation for a rigid body about a fixed axis.
Correct answer: The net work done by torques equals the change in rotational kinetic energy, which is one half the moment of inertia times the angular speed squared.
Explanation: It parallels the linear work–energy theorem.

 

Fill in: Angular momentum equals moment of inertia multiplied by ____ .
Correct answer: angular speed
Explanation: For rotation about a fixed axis, angular momentum equals moment of inertia times angular speed.

 

True or False: In the absence of external torque, total angular momentum of a system remains constant.
Correct answer: True.
Explanation: Conservation of angular momentum applies when net external torque is zero.

 

Multiple choice: The gravitational force between two masses is:
A) Directly proportional to the sum of the masses
B) Inversely proportional to the square of the distance between centers
C) Independent of distance
D) Directly proportional to the square of distance
Correct answer: B) Inversely proportional to the square of the distance between centers
Explanation: Newton’s law of universal gravitation has the inverse square dependence.

 

Short answer: Define gravitational potential energy for two point masses.
Correct answer: It is the energy associated with their separation, equal to negative the gravitational constant times the product of the masses divided by the distance between them.
Explanation: The negative sign reflects attraction and zero at infinite separation.

 

Fill in: For a satellite in a circular orbit, the required centripetal force is provided by ____ .
Correct answer: gravity
Explanation: The gravitational force points toward the center and provides the needed centripetal force.

 

True or False: For a given central mass, a satellite in a lower circular orbit has a shorter period than one in a higher circular orbit.
Correct answer: True.
Explanation: Orbital period increases with the radius of the orbit.

 

Multiple choice: Pressure in a static fluid at depth depends on:
A) Depth and fluid density and gravitational acceleration
B) Volume of the container only
C) Shape of the container only
D) Surface area only
Correct answer: A) Depth and fluid density and gravitational acceleration
Explanation: Pressure equals density times gravitational acceleration times depth added to surface pressure.

 

Short answer: State Archimedes’ principle.
Correct answer: A body wholly or partially submerged in a fluid experiences an upward buoyant force equal to the weight of the fluid displaced.
Explanation: Displaced fluid weight determines the buoyant force.

 

Fill in: The equation of continuity for incompressible steady flow states that area times flow speed is ____ along a streamtube.
Correct answer: constant
Explanation: Mass conservation requires constant volume flow rate.

 

True or False: Bernoulli’s equation for steady, incompressible, nonviscous flow represents conservation of mechanical energy per unit volume along a streamline.
Correct answer: True.
Explanation: It balances pressure energy, kinetic energy, and gravitational potential energy.

 

Multiple choice: Temperature is a measure of:
A) Total internal energy
B) Average translational kinetic energy per particle
C) Total kinetic energy per mole
D) Heat contained in a body
Correct answer: B) Average translational kinetic energy per particle
Explanation: Temperature reflects the average kinetic energy of microscopic motion.

 

Short answer: Define specific heat capacity.
Correct answer: Specific heat capacity is the amount of heat required to raise the temperature of one kilogram of a substance by one degree Celsius.
Explanation: It measures how resistant a substance is to temperature change.

 

Fill in: The first law of thermodynamics states that the change in internal energy equals heat added to the system minus the ____ done by the system.
Correct answer: work
Explanation: Work done by the system reduces its internal energy for a given heat input.

 

True or False: In an isothermal process for an ideal gas, the internal energy remains constant.
Correct answer: True.
Explanation: Internal energy of an ideal gas depends only on temperature.

 

Multiple choice: Entropy is best described as:
A) A measure of total kinetic energy
B) A measure of disorder or the number of accessible microscopic arrangements
C) A measure of total momentum
D) A measure of temperature only
Correct answer: B) A measure of disorder or the number of accessible microscopic arrangements
Explanation: Higher entropy corresponds to more possible microscopic states.

 

Short answer: Define simple harmonic motion.
Correct answer: Simple harmonic motion is periodic motion in which the restoring force is directly proportional to displacement and directed toward the equilibrium position.
Explanation: The force law leads to sinusoidal motion.

 

Fill in: For a mass on a spring with spring constant k and mass m, the period equals 2π times the square root of ____ .
Correct answer: m divided by k
Explanation: The period depends on mass and spring constant only.

 

True or False: Doubling the amplitude of a mass–spring oscillator doubles the period.
Correct answer: False.
Explanation: For a simple mass–spring system, the period is independent of amplitude.

 

Multiple choice: A wave’s speed on a stretched string depends on:
A) Frequency only
B) Wavelength only
C) Tension and linear mass density
D) Amplitude only
Correct answer: C) Tension and linear mass density
Explanation: Speed equals the square root of tension divided by linear mass density.

 

Short answer: Define constructive interference.
Correct answer: Constructive interference occurs when waves combine so that their displacements add to produce a larger amplitude.
Explanation: Peaks align with peaks and troughs with troughs.

 

Fill in: The intensity of a wave is proportional to the square of its ____ .
Correct answer: amplitude
Explanation: Energy transport in many waves scales with amplitude squared.

 

True or False: Sound waves in air are longitudinal waves.
Correct answer: True.
Explanation: Air molecules oscillate parallel to the direction of propagation.

 

Multiple choice: Coulomb’s law states that the electric force between two point charges is:
A) Directly proportional to the product of charges and inversely proportional to the square of distance
B) Directly proportional to the square of distance
C) Independent of distance
D) Only attractive
Correct answer: A) Directly proportional to the product of charges and inversely proportional to the square of distance
Explanation: The force magnitude follows the inverse square law and can be attractive or repulsive.

 

Short answer: Define electric field at a point in space.
Correct answer: The electric field at a point is the force per unit positive test charge that a small positive charge would experience at that point.
Explanation: It describes how charges influence space around them.

 

Fill in: The electric potential difference between two points equals the negative of the line integral of the electric field along a path, which represents work per unit ____ .
Correct answer: charge
Explanation: Potential difference is work done per unit charge by the electric field.

 

True or False: Equipotential surfaces are always perpendicular to electric field lines.
Correct answer: True.
Explanation: No work is done moving along an equipotential surface, so the field is perpendicular.

 

Multiple choice: The equivalent resistance of resistors in series is:
A) The smallest resistance
B) The largest resistance
C) The sum of all resistances
D) The reciprocal of the sum of reciprocals
Correct answer: C) The sum of all resistances
Explanation: The same current flows through each, so voltage drops add.

 

Short answer: State Ohm’s law in words.
Correct answer: The current through a conductor is directly proportional to the potential difference across it, provided the temperature and physical conditions remain constant.
Explanation: The constant of proportionality is the conductance, or its inverse is resistance.

 

Fill in: Electric power delivered to a device equals potential difference times ____ .
Correct answer: current
Explanation: Power equals current multiplied by potential difference.

 

True or False: In a closed circuit, charge is used up as it flows through resistors.
Correct answer: False.
Explanation: Charge is conserved; energy is transferred, not charge consumed.

 

Multiple choice: A bar magnet is cut into two equal halves. Each piece becomes:
A) A north pole only
B) A south pole only
C) A complete magnet with a north and a south pole
D) Not magnetic at all
Correct answer: C) A complete magnet with a north and a south pole
Explanation: Magnetic poles always come in north–south pairs for ordinary magnets.

 

Short answer: State the direction of magnetic force on a moving positive charge using the right-hand rule.
Correct answer: Point the fingers of the right hand in the direction of the charge’s velocity, curl them toward the magnetic field direction, and the thumb points in the direction of the force.
Explanation: The force is perpendicular to both velocity and magnetic field.

 

Fill in: The magnetic flux through a loop equals magnetic field strength times area times the cosine of the angle between the field and the loop’s ____ .
Correct answer: normal
Explanation: Flux measures field lines passing through the surface.

 

True or False: According to Faraday’s law, a changing magnetic flux through a loop induces an electromotive force in the loop.
Correct answer: True.
Explanation: Time-varying flux produces an induced potential difference and current if the circuit is closed.

 

Multiple choice: The induced current in a loop due to a changing magnetic flux has a direction that:
A) Enhances the change in flux
B) Is random
C) Opposes the change in flux
D) Is always clockwise
Correct answer: C) Opposes the change in flux
Explanation: Lenz’s law states the induced current opposes the change causing it.

 

Short answer: Define capacitance.
Correct answer: Capacitance is the ratio of the magnitude of charge stored on one conductor to the potential difference between two conductors.
Explanation: It measures the ability to store electric energy in an electric field.

 

Fill in: The energy stored in a capacitor equals one half times capacitance times the square of the potential ____ .
Correct answer: difference
Explanation: Energy equals one half times capacitance times potential difference squared.

 

True or False: Adding a dielectric material between the plates of an isolated capacitor increases the capacitance.
Correct answer: True.
Explanation: The dielectric reduces the effective electric field, allowing more charge for the same potential difference.

 

Multiple choice: In geometrical optics, the law of reflection states that:
A) The angle of reflection equals the angle of incidence
B) Light always bends toward the normal when entering a denser medium
C) The angle of reflection is always ninety degrees
D) The angle of incidence equals the angle of refraction
Correct answer: A) The angle of reflection equals the angle of incidence
Explanation: Reflection occurs in the plane of incidence with equal angles.

 

Short answer: State Snell’s law in words.
Correct answer: The product of the refractive index of a medium and the sine of the angle of incidence equals the product of the refractive index of the second medium and the sine of the angle of refraction.
Explanation: It describes how light bends when crossing an interface.

 

Fill in: Total internal reflection occurs when light tries to go from a higher refractive index to a lower refractive index at an incidence angle greater than the ____ angle.
Correct answer: critical
Explanation: Beyond the critical angle, refraction cannot occur and all light is reflected.

 

True or False: A converging lens can form a real image or a virtual image depending on object distance.
Correct answer: True.
Explanation: For objects beyond the focal length, the image is real; inside the focal length, the image is virtual.

 

Multiple choice: The photoelectric effect shows that:
A) Light consists only of waves
B) The kinetic energy of emitted electrons depends on light intensity
C) The maximum kinetic energy depends on light frequency with a threshold frequency
D) No electrons are emitted from metal surfaces
Correct answer: C) The maximum kinetic energy depends on light frequency with a threshold frequency
Explanation: Energy is transferred in discrete quanta dependent on frequency.

 

Short answer: Define de Broglie wavelength for a particle.
Correct answer: The de Broglie wavelength equals Planck’s constant divided by the particle’s momentum.
Explanation: It links wave-like behavior with particle motion.

 

Fill in: The nucleus of an atom is composed of ____ and ____ .
Correct answer: protons; neutrons
Explanation: Protons carry positive charge and neutrons are neutral; electrons occupy the surrounding cloud.

 

True or False: In radioactive decay, the total number of nucleons is conserved in alpha decay and beta decay.
Correct answer: True.
Explanation: Nucleon number is conserved even though charge and identity may change.

 

Multiple choice: The period of a simple pendulum of small amplitude depends on:
A) Mass of the bob only
B) Length of the pendulum and gravitational field strength
C) Amplitude only
D) Air resistance only
Correct answer: B) Length of the pendulum and gravitational field strength
Explanation: Period equals two pi times the square root of length divided by gravitational field strength and is independent of mass.

 

Short answer: Define mechanical resonance.
Correct answer: Mechanical resonance occurs when a system is driven at a frequency near its natural frequency, resulting in large amplitude motion.
Explanation: Energy input matches the system’s natural oscillation rate.

 

Fill in: The quality factor of an oscillator describes how slowly energy is lost; higher quality factor means ____ damping.
Correct answer: less
Explanation: A higher quality factor indicates narrower resonance and slower energy loss.

 

True or False: In ideal gases at the same temperature, all molecules have the same speed.
Correct answer: False.
Explanation: Molecular speeds are distributed; they have a range of values.

 

Multiple choice: The average translational kinetic energy of an ideal gas molecule is:
A) Proportional to pressure
B) Proportional to absolute temperature
C) Proportional to volume
D) Independent of temperature
Correct answer: B) Proportional to absolute temperature
Explanation: Temperature measures average translational kinetic energy.

 

Short answer: Define heat conduction.
Correct answer: Heat conduction is the transfer of thermal energy through a material due to a temperature difference without bulk motion of the material.
Explanation: Energy flows from high temperature regions to low temperature regions by particle collisions and vibrations.

 

Fill in: The rate of heat conduction through a slab is proportional to thermal conductivity, area, temperature difference, and inversely proportional to ____ .
Correct answer: thickness
Explanation: A thicker slab reduces the rate of heat flow.

 

True or False: In an adiabatic process, no heat is transferred to or from the system.
Correct answer: True.
Explanation: Adiabatic means heat transfer is zero; work can still change internal energy.

 

Multiple choice: When two objects are in thermal contact and no net heat flows between them, they are:
A) In mechanical equilibrium
B) In thermal equilibrium
C) At the same density
D) Electrically neutral
Correct answer: B) In thermal equilibrium
Explanation: They have the same temperature.

 

Short answer: Define efficiency of a heat engine in words.
Correct answer: Efficiency is the ratio of the useful work output to the heat energy input during the same cycle.
Explanation: It measures how effectively a heat engine converts heat into work.

 

Fill in: The maximum possible efficiency of any heat engine operating between a hot reservoir at temperature Th and a cold reservoir at temperature Tc is 1 minus Tc divided by ____ .
Correct answer: Th
Explanation: The Carnot efficiency equals one minus the cold temperature divided by the hot temperature, with temperatures in kelvin.

 

True or False: No real heat engine can be more efficient than a reversible Carnot engine operating between the same two temperatures.
Correct answer: True.
Explanation: The second law of thermodynamics sets the upper bound.

 

Multiple choice: The potential difference across an inductor that has a changing current is:
A) Proportional to the current
B) Proportional to the rate of change of current
C) Zero
D) Proportional to the square of current
Correct answer: B) Proportional to the rate of change of current
Explanation: The induced potential difference equals inductance times the time rate of change of current.

 

Short answer: Define resonance in an alternating current circuit containing an inductor and a capacitor.
Correct answer: Resonance occurs when the inductive reactance equals the capacitive reactance so that the impedance is minimized and the current is maximized for a given driving frequency.
Explanation: Energy oscillates between the electric field of the capacitor and the magnetic field of the inductor.

 

Fill in: In a simple direct current circuit with a battery and a resistor, the energy delivered by the battery is converted into ____ in the resistor.
Correct answer: thermal energy
Explanation: Electrical energy is dissipated as heat due to resistance.

 

True or False: The direction of polarization of a transverse wave is the direction of the oscillations relative to the direction of travel.
Correct answer: True.
Explanation: Transverse waves oscillate perpendicular to the direction of propagation.

 

Multiple choice: The Rayleigh criterion for resolving two point sources with a circular aperture involves:
A) The angle where the first maximum equals the second maximum
B) The angle where the central maximum of one coincides with the first minimum of the other
C) The angle where both first minima coincide
D) The angle where the central maxima overlap completely
Correct answer: B) The angle where the central maximum of one coincides with the first minimum of the other
Explanation: This gives a practical resolution limit based on diffraction.

 

Short answer: Define diffraction.
Correct answer: Diffraction is the spreading of waves when they encounter an obstacle or pass through an opening, especially when the size is comparable to the wavelength.
Explanation: It arises from interference of parts of the wavefront.

 

Fill in: For a double-slit interference pattern with slit separation d and small angles, the bright fringes occur when d times sine of the angle equals ____ times the wavelength.
Correct answer: an integer
Explanation: Constructive interference occurs for path differences equal to integer multiples of the wavelength.

 

True or False: Polarizing two ideal polarizers at ninety degrees to each other blocks the transmission of linearly polarized light completely.
Correct answer: True.
Explanation: Their transmission axes are perpendicular, so no component passes through the second polarizer.

 

Multiple choice: The binding energy per nucleon is a measure of:
A) The total energy of the atom
B) The energy required to remove one nucleon on average
C) The kinetic energy of the nucleus
D) The electric potential energy only
Correct answer: B) The energy required to remove one nucleon on average
Explanation: It equals the energy difference between the combined nucleus and the separated nucleons divided by the number of nucleons.

 

Short answer: Define half-life in radioactive decay.
Correct answer: Half-life is the time required for half of the nuclei in a sample of a radioactive isotope to decay.
Explanation: It characterizes the exponential decay process.

 

Fill in: The uncertainty principle states that the product of the uncertainty in position and the uncertainty in momentum is on the order of ____ .
Correct answer: Planck’s constant
Explanation: A more precise statement is greater than or equal to reduced Planck’s constant divided by two.

 

True or False: In atomic spectra, emission lines occur when electrons move from higher energy levels to lower energy levels.
Correct answer: True.
Explanation: The energy difference is emitted as a photon of specific frequency.

 

Multiple choice: In special relativity, as the speed of an object approaches the speed of light:
A) Its length increases along the direction of motion
B) Its time interval between events decreases for an observer at rest
C) Its relativistic momentum increases without bound
D) Its mass becomes zero
Correct answer: C) Its relativistic momentum increases without bound
Explanation: The factor that scales momentum grows very large as speed approaches the speed of light.

 

Short answer: Define inertial reference frame.
Correct answer: An inertial reference frame is a frame of reference in which an object not subject to any net external force moves at constant velocity in a straight line.
Explanation: Newton’s first law holds in inertial frames.

 

Fill in: Work is the line integral of force along a path and equals the change in ____ energy when only conservative forces act.
Correct answer: potential
Explanation: Work done by conservative forces equals negative change in potential energy.

 

True or False: The path of a projectile in a uniform gravitational field, neglecting air resistance, is a parabola.
Correct answer: True.
Explanation: Horizontal acceleration is zero and vertical acceleration is constant, producing a parabolic trajectory.

 

Multiple choice: The center-of-mass speed of a system after an internal explosion with no external force:
A) Increases
B) Decreases
C) Remains the same
D) Becomes zero
Correct answer: C) Remains the same
Explanation: With no external force, the momentum of the system and thus center-of-mass motion is unchanged.

 

Short answer: Define elastic collision in one sentence.
Correct answer: An elastic collision is one in which both total kinetic energy and total momentum of the system are conserved.
Explanation: Energy is not transformed into internal energy or deformation.

 

Fill in: A rigid body rotates with constant angular acceleration; the angular displacement equals initial angular speed times time plus one half times angular acceleration times time ____ .
Correct answer: squared
Explanation: This is the rotational kinematic relation.

 

True or False: A conservative force has zero work done around any closed path.
Correct answer: True.
Explanation: The work done by a conservative force depends only on the initial and final positions.

 

Multiple choice: The terminal speed of a falling object through a fluid occurs when:
A) Weight is greater than drag force
B) Drag force is greater than weight
C) Drag force equals weight
D) Buoyant force equals weight
Correct answer: C) Drag force equals weight
Explanation: Net force becomes zero, so acceleration is zero and speed becomes constant.

 

Short answer: Define surface tension.
Correct answer: Surface tension is the energy per unit area required to increase the surface of a liquid due to cohesive forces among molecules at the surface.
Explanation: It causes liquids to minimize surface area.

 

Fill in: Pascal’s principle states that a pressure change applied to an enclosed incompressible fluid is transmitted ____ to every point of the fluid and to the walls of the container.
Correct answer: undiminished
Explanation: The same pressure change appears throughout the fluid.

 

True or False: A wave function in quantum mechanics gives the exact path of a particle at all times.
Correct answer: False.
Explanation: It gives probability amplitudes; only probabilities of finding a particle in regions can be predicted.

 

Multiple choice: The magnetic force on a current-carrying wire in a uniform magnetic field is zero when:
A) The wire is parallel to the field
B) The wire is perpendicular to the field
C) The current is large
D) The wire is a closed loop
Correct answer: A) The wire is parallel to the field
Explanation: The force is proportional to the sine of the angle between current direction and magnetic field.

 

Short answer: Define mechanical advantage of a simple machine.
Correct answer: Mechanical advantage is the ratio of the output force produced by the machine to the input force applied to the machine.
Explanation: It quantifies how a machine multiplies force.

 

Fill in: The condition for static equilibrium of a rigid body is zero net force and zero net ____ .
Correct answer: torque
Explanation: Both translational and rotational effects must balance.

 

True or False: For two resistors in parallel, the equivalent resistance is less than the smallest individual resistance.
Correct answer: True.
Explanation: Parallel paths allow more current for the same potential difference.

 

Multiple choice: The energy of a photon is equal to:
A) Planck’s constant divided by frequency
B) Planck’s constant times frequency
C) Speed of light times wavelength
D) Wavelength divided by Planck’s constant
Correct answer: B) Planck’s constant times frequency
Explanation: Photon energy is directly proportional to frequency.

 

Short answer: Define magnetic flux density in words.
Correct answer: Magnetic flux density is the measure of the magnetic field strength and direction at a point, defined by the force per unit current per unit length on a conductor placed at right angles to the field.
Explanation: It characterizes the magnetic influence on moving charges and currents.

 

Fill in: The speed of light in a medium equals the speed of light in vacuum divided by the medium’s refractive ____ .
Correct answer: index
Explanation: The refractive index describes how much the medium slows light.

 

True or False: The superposition principle states that when two or more waves overlap, the resulting displacement is the algebraic sum of the individual displacements.
Correct answer: True.
Explanation: Interference patterns arise from linear superposition.