Learning
These are 100 original multiple-choice practice questions for PHYS 165 Module 4.
Since exact module content varies by institution, this set assumes Module 4 covers
electric charges and forces, electric fields, electric potential, capacitance, current,
resistance, DC circuits, magnetism, and electromagnetic induction. They are not
official examination questions and are not copied from any textbook, test bank, or
copyrighted source.
Question 1:
The SI unit of electric charge is the:
A. Ampere
B. Coulomb
C. Volt
D. Ohm
Correct answer: B
Rationale:
The coulomb (C) is the SI unit of electric charge.
Question 2:
The elementary charge is approximately:
A. 1.6 × 10⁻¹⁹ C
B. 9.1 × 10⁻³¹ C
C. 6.67 × 10⁻¹¹ C
D. 3.0 × 10⁸ C
Correct answer: A
Rationale:
The elementary charge e ≈ 1.6 × 10⁻¹⁹ C.
Question 3:
Like charges ________ and opposite charges ________.
A. attract; repel
B. repel; attract
,C. attract; attract
D. repel; repel
Correct answer: B
Rationale:
Like charges repel; opposite charges attract.
Question 4:
Coulomb’s law states that the electric force is:
A. F = kq₁q₂/r
B. F = kq₁q₂/r²
C. F = kq₁q₂r²
D. F = kq₁q₂r
Correct answer: B
Rationale:
F = kq₁q₂/r², where k ≈ 8.99 × 10⁹ N·m²/C².
Question 5:
Coulomb’s constant k is approximately:
A. 8.99 × 10⁹ N·m²/C²
B. 6.67 × 10⁻¹¹ N·m²/kg²
C. 9.8 m/s²
D. 3.0 × 10⁸ m/s
Correct answer: A
Rationale:
k = 1/(4πε₀) ≈ 8.99 × 10⁹ N·m²/C².
Question 6:
If the distance between two charges doubles, the electric force:
A. Doubles
B. Halves
C. Quarters
D. Quadruples
Correct answer: C
,Rationale:
F ∝ 1/r², so doubling r gives one-quarter the force.
Question 7:
If both charges double and distance stays the same, the force:
A. Doubles
B. Halves
C. Quadruples
D. Stays the same
Correct answer: C
Rationale:
F ∝ q₁q₂, so doubling both charges gives 4× force.
Question 8:
Two charges of 2 μC each are 0.1 m apart. The force between them is about:
A. 3.6 N
B. 36 N
C. 0.36 N
D. 360 N
Correct answer: A
Rationale:
F = (8.99 × 10⁹)(2 × 10⁻⁶)²/(0.1)² ≈ 3.6 N.
Question 9:
Electric field is defined as:
A. Force per unit charge
B. Charge per unit force
C. Force times charge
D. Charge times distance
Correct answer: A
Rationale:
E = F/q, force per unit positive charge.
, Question 10:
The SI unit of electric field is:
A. N/C
B. C/N
C. N·C
D. N/m
Correct answer: A
Rationale:
Electric field is measured in newtons per coulomb (N/C).
Question 11:
A charge of 3 C experiences a force of 12 N. The electric field is:
A. 4 N/C
B. 36 N/C
C. 0.25 N/C
D. 15 N/C
Correct answer: A
Rationale:
E = F/q = 12/3 = 4 N/C.
Question 12:
The electric field due to a point charge Q at distance r is:
A. kQ/r
B. kQ/r²
C. kQr²
D. kQ²/r
Correct answer: B
Rationale:
E = kQ/r².
Question 13:
Electric field lines point: