Unit 16: Current Electricity + Unit 17: Electric Circuits

1

The purpose of earthing is to:

A Increase voltage B Reduce current C Prevent electric shock D Save energy

2

The resistance of an ideal voltmeter is:

A Zero B Low C Very high D Equal to ammeter

3

A material having very high resistivity is called:

A Conductor B Semiconductor C Insulator D Alloy

4

The SI unit of electric power is:

A Joule B Ampere C Watt D Volt

5

Which factor does NOT affect resistance of a conductor?

A Length B Area C Material D Voltage

6

Which factor increases electric power?

A Decrease in voltage B Decrease in current C Increase in voltage D Increase in resistance

7

Electromotive force (EMF) of a source is the energy supplied per unit:

A Current B Charge C Resistance D Time

8

Potential difference is the work done per unit:

A Charge B Current C Resistance D Time

9

Which graph represents Ohm’s law?

A Current vs Resistance B Voltage vs Resistance C Current vs Voltage D Power vs Voltage

10

The device that converts electrical energy into heat is:

A Fan B Heater C Motor D Generator

11

In household wiring, appliances are connected in:

A Series B Parallel C Mixed D Series-parallel

12

Ohm’s law states that current is directly proportional to:

A Resistance B Voltage C Power D Energy

13

Resistance is defined as the opposition to the flow of:

A Voltage B Charge C Current D Power

14

The internal resistance of a cell causes:

A Increase in terminal voltage B Decrease in terminal voltage C No effect D Infinite current

15

The energy supplied to a circuit depends on:

A Voltage only B Current only C Time, voltage, and current D Resistance only

16

The formula R = ρL/A shows that resistance is directly proportional to:

A Area B Length C Current D Voltage

17

A fuse is used in a circuit to:

A Increase current B Measure voltage C Prevent overheating D Store charge

18

The frequency of AC supply in Pakistan is approximately:

A 25 Hz B 50 Hz C 60 Hz D 100 Hz

19

The purpose of a circuit diagram is to:

A Decorate the circuit B Show actual size C Represent components symbolically D Measure current

20

Electric current is defined as the rate of flow of:

A Energy B Charge C Electrons only D Potential

21

The SI unit of electric current is:

A Volt B Ohm C Ampere D Coulomb

22

When cells are connected in series, the total EMF is:

A Average of EMFs B Difference of EMFs C Sum of EMFs D Product of EMFs

23

A voltmeter is connected in a circuit in:

A Series B Parallel C Series and parallel D Open circuit

24

The SI unit of resistance is:

A Ampere B Volt C Ohm D Watt

25

EMF of a cell is measured when the circuit is:

A Closed B Open C Short D Overloaded