General Science (Physics) MCQs For WBCS Prelims and Mains P1

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14561. Water is boiling in a flask over a burner. To reduce its boiling temperature one must

A

Supply heat from a less intense source

B

Connect the mouth of the flask to a compressor

C

Reduce the surrounding temperature

D

Connect the mount of the flask to an evacuating system

D

Correct Answer: D. Connect the mount of the flask to an evacuating system
Explanation: When pressure decrease the boiling temperature also decreases.

14552. In the International System of Units (S.I.), number of supplementary units is

A

4

B

2

C

3

D

Many

B

Correct Answer: B. 2
Explanation: Supplementary units are the dimensionless units that are used along with the base units to form derived units in the International System (IS). The class of supplementary contains only two purely geometrical units, these are

Radian
Steradian

14693. The emf of a cell does not depend on

A

The material of the anode

B

Electrolyte used

C

The size of the cell

D

The material of the cathode.

C

Correct Answer: C. The size of the cell
Explanation: The emf of a cell does not depend on the size of the cell because electrolytes are not used in emf.

14574. When a body is raised upwards from the Surface of the earth, its weight shall

A

decrease

B

fluctuate

C

increase

D

remain the same

A

Correct Answer: A. decrease
Explanation: The mass stays the same but the weight decreases due to the lack of gravitational pull.

25475. A batsman hits a cricket ball which then rolls on a level ground .Aftercovering a short distance, the ball comes to rest. The ball slows to a stopbecause

A

The batsman did not hit the ball hard enough

B

Velocity is proportional to the force exerted on the ball

C

There is a force on the ball opposing the motion

D

There is no unbalanced force on the ball, so the ball would try to cometo rest

C

Correct Answer: C. There is a force on the ball opposing the motion

15996. The resistance of a 200V - 100W bulb is

A

2

B

400

C

400 when it is not glowing.

D

400 only when it is connected to 200-volt mains

D

Correct Answer: D. 400 only when it is connected to 200-volt mains

25587. The example of “Lentic Habitat” in fresh water community is

A

ponds and swamps

B

waterfalls and rivers

C

ponds and river

D

all of the above

A

Correct Answer: A. ponds and swamps

15628. If a red light is used to illuminate a green leaf and a red flower, it will appear as

A

Black leaf and red flower

B

Black leaf and black flower

C

Green leaf and red flower

D

Red leaf and red flower

A

Correct Answer: A. Black leaf and red flower

15719. The following animal has a similar vision as we have

A

Horse

B

Pigeon

C

Goat

D

Owl

D

Correct Answer: D. Owl

147310. Hydrogen Bombs is based on the principle of

A

Nuclear fusion

B

Nuclear explosion

C

Nuclear fission

D

None of the above

A

Correct Answer: A. Nuclear fusion
Explanation: Nuclear fusion is a reaction in which two or more atomic nuclei are combined to form one or more different atomic nuclei and subatomic particles (neutrons or protons). The difference in mass between the reactants and products is manifested as either the release or the absorption of energy.

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