Atomic structure

Small packets of light is called

• Proton

• quanta

• Photon

• Specturum

Which of the following electromagnetic radiation have greater frequency?

• X - rays

• Ultraviolet rays

• Radio waves

• Visible rays

Two electromagnetic radiations have wave numbers in the ratio 2:3 . Theirs energies per quanta will be in the ratio

• 3 : 2

• 9 : 4

• 4 : 9

• 2 : 3

A radio station is emitting the radiations of frequency 2 × 10⁴ Hz. If its frequency is doubled,

• Wwavelength will be doubled

• Energy per quanta will be doubled

• Wave number will be halved

• All of these

Electromagnetic radiation travels through vacuum at a speed of

• 6.02 × 10¹⁰ms^-1

• 9.1 × 10¹²ms^-1

• 3 × 10⁸ms^-1

• Zero ms^-1

The energy of a proton is directional proportional to

1 wave number

2. frequency

3.wavelength

Select the correct option.

• Both 1 and 2

• Both 1 and 2

• Both 2 and 3

• Only 2

A near UV photon of 300 nm is absorbed by a gas and then re-emitted as two photons . one photon is red with the wavelength 760 nm . Hence , wavelength of the second photon is

• 460nm

• 1060nm

• 496nm

• 300nm

Select the correct statement.

• Visible light consists of electromagnetic waves of oscillating electric and magnetic fields

• In vacuum types of all electromagnetic radiation travel at the same speed

• Both (A) and (B) are correct statements

• None of the above is correct statement

A photo sensitive surface is receiving light of wavelength 5000 Å at the rate of 10^-7 J/s. The number of photons received per second is

• 2.5 × 10¹¹

• 3.0 × 10³²

• 2.5 × 10¹⁸

• 2.5 × 10⁹

As its closest approach, the distance between the mars and the earth is found to be 60 million km. When the planets are at this closest distance, how long would it take to send a radio message from a space probe sent to Mars from Earth?

• 5s

• 200s

• 0.2s

• 20s