Questions and answers for exam Preparation

MCQs

Total Questions : 10

Which of the following statements are correctly associated with ultrasonic waves?
1.These are the acoustic waves of frequencies more than 20,000 Hertz.
2.When possible to use, these waves are preferred over X-rays for getting an image of internal organs because they are not harmful.
3.Their velocity is more than the velocity of sound.

1 only
1 and 2
2 and 3
1 and 3

Discuss Question

Answer: Option A. -> 1 only
:
A

Option:(a)

Question 2.

Paper becomes brittle and yellow with age. Why?
1.The acid content in paper causes brittleness to develop
2.In the presence of visible light, photosensitized oxidation occurs
3.The ultra-violet component of sunlight causes photolysis of cellulose by direct cleavage of the cellulose polymer

1 and 2
2 and 3
1 and 3
1, 2 and 3

Discuss Question

Answer: Option D. -> 1, 2 and 3
:
D

Option:(d)

Question 3.

What is the correct ascending order for frequencies of the following radiations?
1.Visible
2.X-rays
3.Ultraviolet
4.Radio waves

1, 2, 3, 4
3, 2, 4, 1
4, 1, 3, 2
4, 3, 1, 2

Discuss Question

Answer: Option C. -> 4, 1, 3, 2
:
C

Option:(c)

Question 4.

Consider the following statements:
1.A geo-stationary satellite is at an approximate height of 10,000 km.
2.FM transmission of music is a very good quality because the atmospheric or man made noises which are generally frequency variations can do little harm.
Which of the statements given above is/are correct?

1 only
2 only
Both 1 and 2
Neither 1 nor 2

Discuss Question

Answer: Option B. -> 2 only
:
B

Option:(b)

Question 5.

Barium in a suitable form is administered to patients before an X-ray examination of the stomach, because

barium allows X-rays to pass through the stomach on account of its transparency to X-rays
barium compound, like magnesium sulphate helps in cleaning the stomach before X-ray examination
barium is a good absorber of X-rays and this helps the stomach to appear clearly in contrast with the other regions in the picture
barium salts are white in colour and this helps the stomach to appear clearly in contrast with other regions in the picture

Discuss Question

Answer: Option C. -> barium is a good absorber of X-rays and this helps the stomach to appear clearly in contrast with the other regions in the picture
:
C

Option:(c)

Question 6.

Consider the following statements
1.Horsepower is a bigger unit of power than kilowatt.
2.One thousand crore is equal to 1010.
3.One acre is slightly greater than 5000 square metres.
Which of the statements given above is/are correct?

1 and 2
2 only
1 and 3
2 and 3

Discuss Question

Answer: Option D. -> 2 and 3
:
D

Option:(d)

Question 7.

Which one of the following is the correct sequence of the given substances in the decreasing order of their densities?

Steel > Mercury > Gold
Gold > Mercury > Steel
Steel > Gold > Mercury
Gold > Steel > Mercury

Discuss Question

Answer: Option B. -> Gold > Mercury > Steel
:
B

Option:(b)

Question 8.

A person stands at the middle point of a wooden ladder which starts slipping between a vertical wall and the floor of a room, while continuing to remain in a vertical plane. The path traced by a person standing at the middle point of the slipping ladder is

a slipping line
elliptical path
a circular path
a parabolic path

Discuss Question

Answer: Option C. -> a circular path
:
C

Option:(c)

Question 9.

Match List I with List II and choose the correct answer from the codes given below the lists.

Codes:

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

Discuss Question

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

Option:(a)

Question 10.

Assertion (A) : In our houses, the current in A.C. electricity line changes direction 60 times per second.
Reason (R) : The frequency of alternating voltage supplied is 50 Hz.
Codes