GENERAL PHYSICS MULTIPLE CHOICE TEST
Mechanics • Thermodynamics • Electromagnetism • Waves • Modern Physics
Candidate Name: __________________________
Date: ________________________
Student ID: __________________________
Duration: 45 Minutes | 20 Questions
Instructions: Choose the single best answer for each question. Acceleration due to gravity is taken as g = 9.8 m/s² unless
otherwise specified.
Question 1: Which of the following is a fundamental SI base unit?
A. Newton (N)
B. Joule (J)
C. Kelvin (K)
D. Watt (W)
Question 2: An object starts from rest and accelerates uniformly at 3.0 m/s² for 4.0 seconds. How far does it
travel in this time?
A. 12 m
B. 24 m
C. 36 m
D. 48 m
Question 3: According to Newton's Third Law of Motion, action and reaction forces:
A. Act on the same object and cancel each other out
B. Act on different objects and are equal in magnitude and opposite in direction
C. Act on different objects but have unequal magnitudes depending on mass
D. Occur sequentially, with the reaction force occurring after the action force
Question 4: A car of mass 1,000 kg travels around a circular track of radius 50 m at a constant speed of 10
m/s. What is the magnitude of the centripetal force acting on the car?
A. 1,000 N
B. 2,000 N
C. 4,000 N
D. 5,000 N
Question 5: If the kinetic energy of a moving object is quadrupled, by what factor does its linear momentum
increase?
A. 2
B. 4
C. 8
D. 16
Question 6: Two identical spheres of mass M are separated by a distance R. If the distance between their
centers is doubled, the gravitational force between them becomes:
A. Double the initial value
B. Half the initial value
C. One-fourth of the initial value
D. One-eighth of the initial value
Question 7: What happens to the period of a simple pendulum if its length is increased by a factor of 4 while
remaining on Earth?
A. The period doubles
B. The period quadruples
C. The period is halved
D. The period remains unchanged
Question 8: The First Law of Thermodynamics is an expression of which fundamental law?
A. Conservation of Momentum
B. Conservation of Energy
C. Conservation of Mass
D. Conservation of Electric Charge
Question 9: Which state change describes the process of sublimation?
A. Solid directly to gas
B. Gas directly to solid
C. Liquid to gas
D. Solid to liquid
Question 10: Sound waves traveling through air are classified as:
A. Transverse electromagnetic waves
B. Longitudinal mechanical waves
C. Transverse mechanical waves
D. Non-mechanical surface waves
Question 11: When light travels from water (n = 1.33) into air (n = 1.00) at an angle of incidence less than the
critical angle, the light ray:
A. Bends toward the normal and speeds up
B. Bends away from the normal and speeds up
C. Bends toward the normal and slows down
D. Bends away from the normal and slows down
Question 12: Two identical resistors of 10 Ω each are connected in parallel across a 12 V ideal battery. What
is the total current drawn from the battery?
A. 0.6 A
B. 1.2 A
C. 2.4 A
D. 4.8 A
Question 13: Coulomb's law states that the electrostatic force between two point charges is inversely
proportional to:
A. The distance between them
B. The square of the distance between them
C. The sum of the charges
D. The square root of the distance between them
Question 14: A charged particle moves with velocity v parallel to a uniform magnetic field B. What is the
magnetic force exerted on the particle?
A. Zero
B. qvB
C. qvB / 2
D. -qvB
Question 15: Faraday's Law of Induction states that an electromotive force (EMF) induced in a circuit is
proportional to:
A. The magnitude of the magnetic field
B. The area of the loop only
C. The time rate of change of magnetic flux
D. The electrical resistance of the circuit
Question 16: Which of the following electromagnetic waves has the highest frequency?
A. Ultraviolet rays
B. Microwaves
C. Infrared radiation
D. Gamma rays
Question 17: In the photoelectric effect experiment, increasing the intensity of incident light above
threshold frequency causes:
A. An increase in the maximum kinetic energy of emitted electrons
B. An increase in the number of photoelectrons emitted per second
C. A decrease in the stopping potential
D. No change in the emitted photocurrent
Question 18: According to the de Broglie hypothesis, what is the wavelength associated with a particle of
mass m moving with speed v?
A. λ = h / (mv)
B. λ = mv / h
C. λ = h × mv
D. λ = h / (m v²)
Question 19: A radioactive sample has a half-life of 6 hours. If the initial activity is 800 Bq, what will its
activity be after 18 hours?
A. 400 Bq
B. 200 Bq
C. 100 Bq
D. 50 Bq
Question 20: In an elastic collision between two isolated bodies, which of the following quantities are
conserved?
A. Total linear momentum only
B. Total kinetic energy only
C. Both total linear momentum and total kinetic energy
D. Total linear momentum, but kinetic energy is converted into thermal energy
ANSWER KEY & DETAILED EXPLANATIONS
Quick Reference Answer Table:
Q1 - Q4
Q5 - Q8
Q9 - Q12
Q13 - Q16
Q17 - Q20
Q1: C
Q5: A
Q9: A
Q13: B
Q17: B
Q2: B
Q6: C
Q10: B
Q14: A
Q18: A
Q3: B
Q7: A
Q11: B
Q15: C
Q19: C
Q4: B
Q8: B
Q12: C
Q16: D
Q20: C
Detailed Explanations:
Question 1: Correct Answer: C — Kelvin (K) is one of the seven base SI units. Newton, Joule, and Watt are
derived units.
Question 2: Correct Answer: B — Using d = v₀t + ½at²: since v₀ = 0, d = ½(3.0 m/s²)(4.0 s)² = ½(3)(16) = 24 m.
Question 3: Correct Answer: B — Action and reaction forces act simultaneously on different interacting
bodies, so they never cancel each other on a single object.
Question 4: Correct Answer: B — Centripetal force F = mv²/r = (1000 kg × (10 m/s)²) / 50 m = 100,000 / 50 =
2,000 N.
Question 5: Correct Answer: A — Since KE = p²/(2m), momentum p = √(2m × KE). If KE is multiplied by 4, p is
multiplied by √4 = 2.
Question 6: Correct Answer: C — By Newton's Law of Universal Gravitation, F ∝1/R². Doubling the distance
decreases the force by a factor of 2² = 4 (one-fourth).
Question 7: Correct Answer: A — The period is T = 2π√(L/g). If length L is quadrupled, T is multiplied by √4 =
2.
Question 8: Correct Answer: B — The First Law of Thermodynamics (ΔU = Q - W) is the principle of
conservation of energy applied to thermodynamic systems.
Question 9: Correct Answer: A — Sublimation is the phase transition directly from solid to gas without
passing through an intermediate liquid phase.
Question 10: Correct Answer: B — Sound in air requires a medium (mechanical) and oscillates parallel to the
direction of propagation (longitudinal compressions and rarefactions).
Question 11: Correct Answer: B — Passing into an optically less dense medium (lower refractive index)
causes light to accelerate and refract away from the normal.
Question 12: Correct Answer: C — Equivalent resistance R_eq = (10 × 10)/(10 + 10) = 5 Ω. Total current I = V /
R_eq = 12 V / 5 Ω = 2.4 A.
Question 13: Correct Answer: B — Coulomb's Law is F = k·|q₁q₂| / r², which follows an inverse-square
relationship with distance r.
Question 14: Correct Answer: A — The magnetic Lorentz force is F = q(v × B) = qvB·sin(θ). When v is parallel
to B, θ = 0° and sin(0°) = 0, so F = 0.
Question 15: Correct Answer: C — Faraday's Law gives EMF ε = -dΦ_B/dt, showing EMF is proportional to the
time rate of change of magnetic flux through the circuit.
Question 16: Correct Answer: D — In the electromagnetic spectrum, gamma rays have the shortest
wavelength and highest frequency (and highest photon energy).
Question 17: Correct Answer: B — Light intensity corresponds to photon flux. More photons strike per
second, ejecting more electrons per second (higher photocurrent). Max KE depends only on frequency.
Question 18: Correct Answer: A — The de Broglie wavelength is λ = h/p = h/(mv), where h is Planck's
constant.
Question 19: Correct Answer: C — Number of half-lives elapsed n = 18 / 6 = 3. Remaining activity = 800 / 2³ =
800 / 8 = 100 Bq.
Question 20: Correct Answer: C — By definition, an elastic collision conserves both total linear momentum
and total kinetic energy.