Questions and answers for exam Preparation

MCQs

Total Questions : 150 | Page 2 of 15 pages

Question 11. Microphone is a device in which

Sound waves are directly transmitted
Electrical energy is converted into sound waves directly
Sound waves are converted into electrical energy and then reconverted into sound after transmission
Amplification is not required at all

Discuss Question

Answer: Option C. -> Sound waves are converted into electrical energy and then reconverted into sound after transmission
:
C
Option:(c)

Question 12. Match List I with List II and select the correct answer from the codes given below the lists:

Codes:

A-2,B-1,C-4,D-3
A-3,B-4,C-2,D-1
A-3,B-1,C-4,D-2
A-4,B-3,C-2,D-1

Discuss Question

Answer: Option B. -> A-3,B-4,C-2,D-1
:
B
Option:(b)

Question 13. Match List I (Parameters of Light) with List II (their Dependence) and select the correct answer from the codes given below the lists:

Codes:

A-2,B-4,C-1,D-3
A-3,B-4,C-2,D-1
A-3,B-1,C-2,D-4
A-4,B-2,C-3,D-1

Discuss Question

Answer: Option B. -> A-3,B-4,C-2,D-1
:
B
Option:(b)

Question 14. If a potato is placed on a pure paper plate which is white and unprinted and put in a microwave oven, the potato heats up but the paper plate does not. This is because

potato is mainly made up of starch whereas paper is mainly made up of cellulose
potato transmits microwaves whereas paper reflects microwaves
potato contains water whereas paper does not contain water
potato is a fresh organic material whereas paper is a dead organic material

Discuss Question

Answer: Option C. -> potato contains water whereas paper does not contain water
:
C
Option:(c)

Question 15. What is the principle by which a cooling system (Radiator) in a motor car works?

Conduction only
Convection
Radiation only
Both convection and radiation

Discuss Question

Answer: Option D. -> Both convection and radiation
:
D
Option:(d)

Question 16. Consider the following statements
1.Light of longer wavelength is scattered much more than the light of shorter wavelength.
2.The speed of visible light in water is 0.95 times the speed in vacuum.
3.Radio waves are produced by rapidly oscillating electrical currents.
4.To detect the overspeeding vehicles, police use the Doppler effect of reflected short radio waves.
Which of these statements are correct?

1 and 2
1 and 3
2 and 4
3 and 4

Discuss Question

Answer: Option D. -> 3 and 4
:
D
Option:(d)

Question 17. Assertion (A): A piece of copper and a piece of glass are heated to the same temperature. When touched, thereafter, the copper piece appears hotter than the glass piece.
Reason (R) : The density of copper is more than that of glass.
Codes

Both A and R are true and R is the correct explanation of A
Both A and R are true but R is not a correct explanation of A
A is true but R is false
A is false but R is true

Discuss Question

Answer: Option B. -> Both A and R are true but R is not a correct explanation of A
:
B
Option:(b)

Question 18. Assertion (A): A diamond will shine more than a glass imitation cut to the same shape.
Reason (R) : The refractive index of diamond is less than that of glass.In context of the above two statements, which one of the following is correct?

Both A and R are true and R is the correct explanation of A
Both A and R are true and R is not a correct explanation of A
A is true but R is false
A is false but R is true

Discuss Question

Answer: Option C. -> A is true but R is false
:
C
Option:(c)

Question 19. Suppose a rocket ship is receding from the earth at a speed of 2/10th the velocity of light. A light in the rocket ship appears blue to the passengers on the ship. What colour would it appear to an observer on the earth?

Blue
Orange
Yellow
Indigo

Discuss Question

Answer: Option A. -> Blue
:
A
Option: (a)

Question 20. Assertion (A): In the visible spectrum of light, red light is more energetic than green light.
Reason (R) : The wavelength of red light is more than that of green light.Codes