Home
Current Affairs January 2024

What is the correct answer?

4

For an electron orbiting in a hydrogen atom, the necessary centripetal force keeping it in orbit is provided by

A. the electrical attraction between the negatively charged electron and the positively charged porton

B. the high speed of the electron

C. the low speed of the electron

D. gravity

Correct Answer :

A. the electrical attraction between the negatively charged electron and the positively charged porton


Related Questions

What is the correct answer?

4

Tap water is placed in an open pad and allowed to evaporate. After some time the temperature of water

A. increases to a great extent

B. increases slightly

C. decreases slightly

D. decreases rapidly

What is the correct answer?

4

The Solar System lies near the edge of a galaxy known as

A. The Milky Way

B. Radio Galaxy

C. Andromeda Nebula

D. Magellanic Clouds

What is the correct answer?

4

The brightest planet in the Solar System is

A. Jupiter

B. Mercury

C. Venus

D. Sirius

What is the correct answer?

4

Cosmic rays are

A. powerful X-rays falling on the earth from space

B. ultraviolet rays from the sun

C. gamma rays from radioactive minerals

D. very energetic radiation falling upon the earth from outer space consisting chiefly of charged particles

What is the correct answer?

4

Some persons are not able to see distant objects clearly because the image of the object is focused in front of the retina. This defect is known as

A. short sight

B. long sight

C. astigmatism

D. presbyopia

What is the correct answer?

4

A rod of brass is held in hand and rubbed with fur. The rod is found to have

A. no charge

B. positive charge

C. negative charge

D. can't be said

What is the correct answer?

4

The first Indian Satellite launched from a Russian Cosmodrome on April 16, 1975 was named

A. Bhaskara

B. Insat I-A

C. Aryabhatta

D. SLV-l

What is the correct answer?

4

Which of the following can produce electricity?

A. resistor

B. thermocouple

C. light bulb

D. neon tube

What is the correct answer?

4

A man stands in a lift which accelerates upwards. The resultant reaction force on the floor of the lift is

A. greater than the weight of the man

B. less than the weight of the man

C. same as the weight of the man

D. zero

What is the correct answer?

4

The cell that can be recharged, after it has run down, by passing a direct current through it from a source of current is

A. Voltaic cell

B. Leclanche cell

C. Dry cell

D. An accumulator

What is the correct answer?

4

The audible range of a normal human ear is frequencies ranging from

A. 10000 to 20000 Hz

B. 50 to 15000 Hz

C. 20 to 20000 Hz

D. 15 to 50000 Hz

What is the correct answer?

4

Of the following types of electromagnetic radiation which has the longest wavelength?

A. ultraviolet rays

B. gamma rays

C. radio waves

D. infrared waves

What is the correct answer?

4

Which mirror is used as a rear view mirror in Vehicles?

A. Parabolic

B. Convex

C. Concave

D. Plain

What is the correct answer?

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

What is the correct answer?

4

To get 5 images of a single object one should have two plane mirrors inclined at an angle of

A. 72°

B. 60°

C. 36°

D. 90°

What is the correct answer?

4

In a microphone

A. sound energy is converted into electrical energy

B. electrical energy is converted into sound energy

C. sound energy is converted into mechanical energy

D. mechanical energy is converted into sound energy

What is the correct answer?

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

What is the correct answer?

4

A tube light works on the principle of

A. chemical, heating and magnetic effects of electricity

B. discharge of electricity through gases

C. the action of ultraviolet radiation on certain fluorescent materials

D. Both (b) and (c) above

What is the correct answer?

4

The line on earth's surface passing through the places having zero dip is called the magnetic equator. This passes through

A. Thumba

B. Delhi

C. Mumbai

D. Sriharikota

What is the correct answer?

4

A nuclear reactor is said to have become 'critical' when

A. it stops due to malfunctioning

B. it starts emitting dangerous radioactive radiations

C. it is shut down to avoid explosion

D. it is ready to produce controlled energy

What is the correct answer?

4

Under similar conditions of temperature and pressure, the velocity of sound is maximum in

A. helium

B. argon

C. hydrogen

D. oxygen

What is the correct answer?

4

An ohm is a unit of

A. potential difference

B. resistance

C. current

D. All the above

What is the correct answer?

4

Which of the following is fissionable?

A. U-234

B. U-235

C. U-238

D. Both (b) and (c)

What is the correct answer?

4

The instrument used to determine the RD (Relative Density) of a liquid by the principle of floatation is

A. Hygrometer

B. Hypsometer

C. Hydrometer

D. Densimeter

What is the correct answer?

4

Out of the following which is an insulator?

A. Silver

B. Copper

C. Nichrome

D. Dry wood

What is the correct answer?

4

A solid ball of metal has a spherical cavity inside it. When the ball is heated the volume of the cavity will

A. increase

B. decrease

C. remain unaffected

D. have its shape changed

What is the correct answer?

4

The study of astronomy include a

A. astrology

B. astrophysics

C. astrometry

D. Both (b) and (c) above

What is the correct answer?

4

The base of an electric iron is brightly polished mainly

A. to make it smooth and frictionless

B. to make it rust - proof

C. to reduce heat loss by radiation

D. to make it more durable

What is the correct answer?

4

To produce beats it is necessary to have two waves

A. travelling in opposite direction

B. of slightly different frequencies

C. of equal wavelength

D. of equal amplitude

What is the correct answer?

4

Which is the densest planet of the solar system?

A. Sun

B. Jupiter

C. Mercury

D. Earth