physics MCQs - 10th class Chapter 07 Mcqs

1

The process by which electrons are emitted by a hot metal surface is known as

A

boiling

B

evaporation

C

conduction

D

thermionic emission

2

The particles emitted from a hot cathode surface are

A

positive ions

B

negative ions

C

protons

D

electrons

3

The logical operation performed by the gate shown with inputs A and B resulting in X = A.B is

A

AND

B

NOR

C

NAND

D

OR

4

An AND gate can be formed by using two

A

NOT gates

B

OR gates

C

NOR gates

D

NAND gates

5

The output of a two-input NOR gate is 1 when:

A

A is '1' and B is '0'

B

A is '0' and B is '1'

C

both A and B are '0'

D

both A and B are '1'

6

If X = A.B, then X is '1' when:

A

A and B are '1'

B

A or B is '0'

C

A is '0' and B is '1'

D

A is '1' and B is '0'

7

The output of a NAND gate is '0' when

A

both of its inputs are '0'

B

both of its inputs are '1'

C

any of its inputs is '0'

D

any of its inputs is '1'

8

The branch of applied physics dealing with the control of electron motion is called

A

Mechanics

B

Thermodynamics

C

Optics

D

Electronics

9

In 1897, J.J. Thomson observed the deflection of cathode rays by

A

gravity only

B

sound waves

C

light waves

D

electric and magnetic fields

10

Cathode rays are particles that carry a

A

positive charge

B

negative charge

C

neutral charge

D

no charge

11

The process of emission of electrons from a hot metal surface is called

A

photoelectric emission

B

field emission

C

secondary emission

D

thermionic emission

12

Thermionic emission can be produced by heating a fine tungsten filament with a typical voltage of

A

1.5 V

B

6 V

C

12 V

D

220 V

13

In an electron gun, the electrons are accelerated towards a

A

negative anode

B

cylindrical anode with positive potential

C

neutral grid

D

fluorescent screen

14

The deflection of electrons towards a positive plate in an electric field is due to the force

A

F=mg

B

F=G(m1m2/r^2)

C

F=qE

D

F=qvB

15

The instrument used to display the magnitudes of changing electric currents or potentials is the

A

Voltmeter

B

Ammeter

C

Galvanometer

D

Cathode-Ray Oscilloscope

16

Which of the following is NOT a main component of a CRO?

A

Electron gun

B

Deflecting plates

C

Microphone

D

Fluorescent screen

17

In a CRO, the brightness of the spot on the screen is controlled by the

A

Anode

B

Cathode

C

Grid G

D

Deflecting plates

18

The fluorescent screen of a CRO is coated with a thin layer of

A

Tungsten

B

Copper

C

Phosphor

D

Aluminum

19

A material that gives light as a result of bombardment by fast-moving electrons is

A

an insulator

B

a conductor

C

a semiconductor

D

phosphor

20

Quantities whose values vary continuously are known as

A

digital quantities

B

analogue quantities

C

vector quantities

D

scalar quantities

21

The branch of electronics that deals with quantities varying continuously is

A

digital electronics

B

power electronics

C

analogue electronics

D

optoelectronics

22

Digital electronics uses how many digits to represent data?

A

1

B

2

C

8

D

10

23

A signal that can have only two discrete values is called a

A

analogue signal

B

continuous signal

C

digital signal

D

sine wave

24

A circuit that converts an analogue signal into a digital signal is called

A

DAC

B

CRO

C

ADC

D

LDR

25

A circuit that converts a digital signal into an analogue signal is called

A

ADC

B

DAC

C

OR Gate

D

AND Gate

26

A given statement being either 'true' or 'false' is an example of a

A

analogue variable

B

continuous variable

C

random variable

D

binary variable

27

The special algebra used to describe logic operations is called

A

Linear Algebra

B

Vector Algebra

C

Boolean Algebra

D

Matrix Algebra

28

The AND operation is represented by which symbol?

A

+ (plus)

B

. (dot)

C

- (minus)

D

/ (slash)

29

The Boolean expression for a two-input AND operation is

A

X = A + B

B

X = A - B

C

X = A.B

D

X = A / B

30

The output of an AND gate is HIGH ('1') only when

A

any input is HIGH

B

all inputs are LOW

C

inputs are different

D

all inputs are HIGH

31

The OR operation is represented by which symbol?

A

. (dot)

B

x (cross)

C

+ (plus)

D

- (minus)

32

The Boolean expression for a two-input OR operation is

A

X = A.B

B

X = A + B

C

X = NOT A

D

X = A - B

33

The output of an OR gate is LOW ('0') only when

A

all inputs are HIGH

B

any input is HIGH

C

all inputs are LOW

D

inputs are different

34

A circuit with switches connected in parallel represents which logical operation?

A

AND

B

NOT

C

NAND

D

OR

35

The NOT operation is also known as

A

inversion

B

conjunction

C

disjunction

D

addition

36

The electronic circuit which implements the NOT operation is known as a

A

Buffer

B

Inverter

C

Follower

D

Amplifier

37

A NOT gate has how many inputs and outputs?

A

2 inputs, 1 output

B

1 input, 2 outputs

C

1 input, 1 output

D

2 inputs, 2 outputs

38

A NAND gate is formed by an AND gate followed by a

A

OR gate

B

NOT gate

C

AND gate

D

NOR gate

39

The Boolean expression for a two-input NAND gate is

A

X = A + B

B

X = A.B

C

X = A + B (bar)

D

X = A.B (bar)

40

A small circle at the output of a standard logic gate symbol represents the

A

OR operation

B

AND operation

C

NOT operation

D

XOR operation

41

A NOR gate is formed by an OR gate followed by a

A

NOT gate

B

AND gate

C

OR gate

D

NAND gate

42

The Boolean expression for a two-input NOR gate is

A

X = A.B

B

X = A + B

C

X = A.B (bar)

D

X = A + B (bar)

43

In the house safety alarm circuit, what component acts as a switch that is closed in light?

A

Capacitor

B

Resistor

C

Diode

D

LDR

44

An LDR (Light Depending Resistor) has high resistance in the

A

light

B

dark

C

day

D

presence of heat

45

A standard grouping of eight bits in digital electronics is called a

A

nibble

B

word

C

byte

D

bit

46

The process of transforming information into 1's and 0's is called

A

amplification

B

rectification

C

digitization

D

modulation

47

The cathode in an electron gun is

A

electrically heated

B

cooled

C

kept at positive potential

D

made of glass

48

In a CRO, the Y-plates are responsible for which deflection?

A

Horizontal

B

Diagonal

C

Circular

D

Vertical

49

The picture tube in a TV set is an example of a

A

transistor

B

logic gate

C

cathode-ray tube

D

capacitor

50

The algebra of logic which deals with variables that can have two values, 'true' or 'false', is

A

conventional algebra

B

Boolean algebra

C

geometric algebra

D

abstract algebra