Unit 16: Current Electricity

1

Which particles are responsible for electric current in metallic conductors?

A Protons B Neutrons C Electrons D Ions

2

To convert a galvanometer into a voltmeter, we connect:

A Low resistance in parallel B Low resistance in series C High resistance in series D High resistance in parallel

3

A voltmeter is connected in a circuit in:

A Series B Parallel C Series and parallel D Open circuit

4

The SI unit of resistivity is:

A Ohm B Ohm meter C Volt per ampere D Ampere meter

5

To convert a galvanometer into an ammeter, we connect:

A High resistance in series B Low resistance in parallel C High resistance in parallel D Low resistance in series

6

The resistance of an ideal voltmeter is:

A Zero B Low C Very high D Equal to ammeter

7

The experiment for demonstration of resistance verifies:

A Ohm’s Law B Newton’s Law C Faraday’s Law D Coulomb’s Law

8

The slope of V-I graph represents:

A Current B Voltage C Resistance D Power

9

Resistance increases with increase in:

A Area B Length C Temperature (for metals) D Both B and C

10

Alternating current (AC) changes its direction:

A Once B After every hour C Periodically D Never

11

The SI unit of EMF is:

A Ampere B Coulomb C Volt D Ohm

12

Direct current (DC) flows in:

A Both directions alternately B One direction only C Random directions D Circular paths only

13

Electric current is defined as the rate of flow of:

A Energy B Charge C Electrons only D Potential

14

EMF of a cell is measured when the circuit is:

A Closed B Open C Short D Overloaded

15

An increase in temperature of a metallic conductor generally causes its resistance to:

A Decrease B Remain same C Increase D Become zero

16

Copper is widely used for electrical wiring because it has:

A High resistivity B Low resistivity C No resistance D High density

17

The frequency of AC supply in Pakistan is approximately:

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

18

Ohm’s Law states that current through a conductor is directly proportional to:

A Resistance B Voltage C Power D Charge

19

One volt is equal to:

A One joule per coulomb B One coulomb per joule C One ampere per second D One ohm per ampere

20

The main advantage of AC over DC is that it can be:

A Stored easily B Transmitted over long distances easily C Produced only by batteries D Measured easily

21

The internal resistance of a cell causes:

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

22

Which quantity remains constant in an ohmic conductor at constant temperature?

A Current B Voltage C Resistance D Charge

23

Which instrument is most sensitive for detecting small currents?

A Ammeter B Voltmeter C Galvanometer D Ohmmeter

24

Which of the following is a source of DC?

A AC generator B Battery C Alternator D Transformer

25

The opposition offered by a conductor to the flow of current is called:

A Potential difference B Resistance C EMF D Charge