Question 1

What is the SI unit of electric charge?

Accepted Answer

Coulomb. Electric charge is measured in coulomb in the SI system. One coulomb is the charge carried by a 1 ampere current in 1 second. Charge is a fundamental quantity in electricity.

Question 2

Ohm’s law is correctly written as?

Accepted Answer

V = IR. Ohm’s law states that voltage equals current times resistance. It is written as V = IR for an ohmic conductor at constant temperature. It helps relate V, I, and R in circuits.

Question 3

A potential difference of 12 V produces a current of 3 A in a resistor. What is the resistance?

Accepted Answer

36 Ω. Use Ohm’s law R = V/I. Substituting V = 12 and I = 3 gives R = 12/3 = 4 Ω. Resistance is measured in ohm (Ω).

Question 4

Two resistors 2 Ω and 3 Ω are connected in series. Their equivalent resistance is?

Accepted Answer

0.5 Ω. In series, resistances add directly. So Req = 2 + 3 = 5 Ω. Series connection increases total resistance.

Question 5

For two resistors R1 and R2 in parallel, the equivalent resistance is?

Accepted Answer

Req = (R1 + R2)/2. In a parallel combination, 1/Req = 1/R1 + 1/R2. For two resistors, this simplifies to Req = (R1R2)/(R1 + R2). Parallel connection reduces the equivalent resistance below the smallest resistor.

Electricity — Set 1