Half Book 2

1

Which electromagnetic wave has the shortest wavelength?

A X-rays B Ultraviolet rays C Gamma rays D Visible light

2

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

A Current B Charge C Resistance D Time

3

The main source of electricity in homes is:

A Battery B Generator C Power station D Solar cell only

4

Which scientist discovered the magnetic effect of electric current?

A Michael Faraday B Hans Christian Oersted C James Clerk Maxwell D Isaac Newton

5

A relay is an electrically operated:

A Capacitor B Switch C Resistor D Battery

6

Atoms of the same element with different mass numbers are called:

A Isobars B Isotones C Isotopes D Nuclides

7

X-rays are mainly used for

A Cooking B Communication C Medical diagnosis D Heating

8

The SI unit of electric current is:

A Volt B Ohm C Ampere D Watt

9

The frequency of AC supply in Pakistan is approximately:

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

10

Lenz’s law is a consequence of conservation of:

A Charge B Energy C Mass D Momentum

11

Which law gives magnitude of induced emf?

A Ohm’s law B Faraday’s law C Lenz’s law D Kirchhoff’s law

12

Which is NOT a source of background radiation?

A Cosmic rays B Rocks C Soil D Radio waves

13

A step-up transformer increases:

A Current B Power C Voltage D Resistance

14

Which biasing allows maximum current through a diode?

A Reverse biasing B Zero biasing C Forward biasing D Negative biasing

15

The main source of energy of the Sun is:

A Nuclear fission B Chemical reaction C Nuclear fusion D Radioactivity

16

Electricity is widely used because it is:

A Expensive B Difficult to control C Easy to transmit D Dangerous

17

Which color has the longest wavelength in visible light?

A Blue B Green C Yellow D Red

18

The main advantage of digital electronics is:

A Complexity B Noise immunity C High cost D Large size

19

Quantum computers are expected to be very powerful in:

A Simple calculations B Complex problem solving C Word processing D Printing

20

When a diode is forward biased, it:

A Offers high resistance B Does not conduct C Conducts current D Breaks down

21

The basic unit of information in quantum computing is:

A Bit B Qubit C Byte D Gate

22

Half-life of a radioactive substance is the time required for:

A All atoms to decay B Half of the atoms to decay C One atom to decay D Radiation to stop

23

Which appliance uses maximum power?

A Electric bulb B Electric iron C Electric bell D Radio

24

Electric current is defined as the rate of flow of:

A Energy B Charge C Electrons only D Potential

25

Which electromagnetic waves are used in satellite communication?

A Ultraviolet rays B Microwaves C X-rays D Gamma rays