Electric Charge & Potential Difference — Homi Bhabha Class 9 Physics MCQs with Solutions
Free Homi Bhabha Class 9 Physics Electric Charge & Potential Difference MCQs with step-by-step solutions (8 questions). Part of Electricity & Magnetism. Practise online on Prepizo — no login needed.
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Questions with solutions
Q1 — Electric Charge & Potential Difference · medium · theory
The SI unit of electric charge is the:
A. volt
B. ampere
C. ohm
D. coulomb ✓ Correct
Solution: Charge is measured in coulombs (C); 1 C = 1 ampere × 1 second.
Q2 — Electric Charge & Potential Difference · medium · numerical
If a current of 2 A flows through a wire for 5 s, the charge that passes through it is:
A. 10 C ✓ Correct
B. 2.5 C
C. 0.4 C
D. 7 C
Solution: Charge $Q = I \times t = 2 \times 5 = 10$ C.
Q3 — Electric Charge & Potential Difference · medium · theory
The potential difference between two points is defined as the work done in moving a unit charge between them, and its SI unit is the:
A. coulomb
B. watt
C. ampere
D. volt ✓ Correct
Solution: Potential difference $V = \dfrac{W}{Q}$; its unit is the volt (1 V = 1 J/C).
Q4 — Electric Charge & Potential Difference · hard · numerical
If 20 J of work is done in moving 4 C of charge between two points, the potential difference between them is:
A. 80 V
B. 5 V ✓ Correct
C. 24 V
D. 0.2 V
Solution: $V = \dfrac{W}{Q} = \dfrac{20}{4} = 5$ V.
Q5 — Electric Charge & Potential Difference · medium · theory
A material through which electric charge flows easily is called a:
A. insulator
B. conductor ✓ Correct
C. dielectric
D. semiconductor only
Solution: Conductors (e.g. metals) allow charge to flow; insulators (e.g. rubber) resist it.
Q6 — Electric Charge & Potential Difference · easy · theory
What is the SI unit of potential difference?
A. Ampere
B. Coulomb
C. Volt ✓ Correct
D. Ohm
Solution: Potential difference is measured in volts. 1 volt = 1 joule of work per coulomb of charge (1 V = 1 J/C).
Q7 — Electric Charge & Potential Difference · medium · numerical
How much work is done in moving a charge of 5 C through a potential difference of 12 V?
A. 60 J ✓ Correct
B. 0.42 J
C. 2.4 J
D. 17 J
Solution: Work W = QV = 5 C × 12 V = 60 J.
Q8 — Electric Charge & Potential Difference · hard · numerical
When a charge of 2 C is moved between two points, 48 J of work is done. If the potential difference is then doubled while the same 2 C charge is moved, what work is done?
A. 48 J
B. 192 J
C. 96 J ✓ Correct
D. 24 J
Solution: Original V = W/Q = 48/2 = 24 V. Doubling gives 48 V. New work W = QV = 2 × 48 = 96 J.