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Current Affairs January 2024

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4

When sound waves travel from one medium to another, the quantity which remains unchanged is its

A. speed

B. frequency

C. wavelength

D. All the above

Correct Answer :

B. frequency


Related Questions

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4

The Indian Satellite System used for domestic communications, television and meteorology is known as

A. INSAT

B. Bhaskara

C. Aryabhatta

D. All the above

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4

Electron-volt is a unit of

A. power

B. velocity

C. energy widely used in nuclear physics

D. number of electrons

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Which of the following revolves round the nucleus in an atom?

A. protons

B. electrons

C. neutrons

D. positrons

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4

The inability of a body to change its state of rest or uniform motion along a straight line is called its

A. momentum

B. velocity

C. acceleration

D. inertia

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4

Holography is the technique of

A. taking photos of various objects

B. recording and reproducing three dimensional images

C. tracing out planets and stars in the sky

D. transmitting light waves

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4

Solids have definite shapes. This is because

A. the forces of cohesion of the molecules within are very much less in them

B. the forces of cohesion are very large

C. the forces of adhesion are large

D. the forces of adhesion are less

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4

Metals are good conductors of heat because

A. they contain free electrons

B. their atoms are relatively far apart

C. their atoms collide frequently

D. they have reflecting surfaces

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4

The completely dark portion of a shadow of an object is known as

A. umbra

B. penumbra

C. image

D. black portion of light

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4

Which of the following is known as freon?

A. Liquid ammonia

B. Carbon tetrafluoride

C. Dichloro-difluoro-methane

D. Sulphur dioxide

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4

We see the sun before it actually rises on the horizon. This is due to

A. refraction

B. reflection

C. total internal reflection

D. parallax

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4

Thick brick walls are used in the construction or a cold storage because bricks

A. are good conductors of heat

B. are cheaper

C. are easily obtained

D. are bad conductors of heat

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4

A radio set that uses valves does not start operating immediately when it is switched on whereas a set containing only tranaistors operates immediately. The reason for this is that

A. the valve filaments have low resistance

B. valve-radio sets work at a higher voltage

C. transistor set has a low resistance

D. filaments of the valves cake time to beat up and function

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4

When the resistance of a circuit increases the current will

A. increase

B. decrease

C. remain the same

D. None of the above

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4

A star contains

A. about 75% of hydrogen

B. 22% helium

C. traces of most other elements including oxygen, neon, carbon and nitrogen

D. All the above

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4

Why is it cool near an open pond on a hot summer day?

A. Evaporation at the surface causes cooling

B. The heat obsorbed at the surface is passed on to the bottom

C. Because of impurity in the water

D. Because of convection currents set up inside water

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4

A ship sailing from a river to the sea

A. sinks less in the sea

B. sinks more in the sea

C. neither sinks more nor less in the sea

D. sinking more or less depends on sea

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4

A man stands on the pan of a balance holding a fish in his right hand and bucket of water in his left hand. If he transfers the fish into the bucket, the total weight on the pan

A. increases

B. decreases

C. remains the same

D. first increases and then decreases

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4

The brightest planet in the Solar System is

A. Jupiter

B. Mercury

C. Venus

D. Sirius

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4

Drinks kept in a vacuum flask remain hot or cold as the case may be for a long time because

A. both walls are silvered on the vacuum side

B. there is vacuum between the double walls

C. the cork is a poor conductor of heat

D. of all the above

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4

A sensitive instrument susceptible to magnetic infiuence can be protected from external magnetic field by

A. enclosing it in a thick walled iron box

B. wrapping it with an insulator

C. by placing it inside a glass case

D. by surrounding it with fine copper gauze

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4

Acoustics' la a branch or study dealing with

A. historical sites

B. architecture

C. sound

D. trigonometry

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4

The direction of heat flow between two objects depends on

A. their heat contents

B. their masses

C. their temperatures

D. whether they are in solid, liquid or gaseous state

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4

The device used to record the sound is

A. a microphone

B. a headphone

C. a phonograph

D. an amplifier

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4

When light travels from one medium to another there is a change in its

A. velocity

B. wavelength

C. frequency

D. Both (a) and (b) above

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4

A device used in a ship for the purpose of measuring the depth of the sea is

A. an altimeter

B. a fathometer

C. a hydrometer

D. a sonometer

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4

Which of the following is fissionable?

A. U-234

B. U-235

C. U-238

D. Both (b) and (c)

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4

Choose the correct answer

A. Microphone converts sound energy into electrical energy.

B. Electric fan converts electrical energy into mechanical energy.

C. Battery converts chemical energy into electrical energy.

D. All the above

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4

The colour of a star is an indication of its

A. distance from the earth

B. age

C. temperature

D. size

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4

Which of the following is not electromagnetic waves?

A. heat waves

B. sound waves

C. radio waves

D. light waves

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Diamond shines because of its

A. purity

B. hardness

C. high density

D. high refractive index and low critical angle