1. Radioactive decay of the nucleus emits ____________
a) Ultraviolet rays
b) X-Rays
c) Infra-red
d) Gamma rays
Explanation: Gamma rays lie in the upper frequency of the electromagnetic spectrum. It is produced in a nuclear reaction and also emitted in radioactive nuclei. Due to their high penetration power, they are used to destroy cancer cells
2. What is the frequency of a photon having energy 3.3 X 10-30 J?
a) 4.0 X 1013 Hz
b) 5.0 X 1013 Hz
c) 6.0 X 1013 Hz
d) 7.0 X 1013 Hz
Explanation: Here, E = 3.3 X 10-30 J
Frequency, v =?
We know, Energy = hv, where h is the Planck’s Constant
Therefore, v = E/h
= 3.3 X 10-30J/6.6 X 10-34Js
= 5 X 1013 Hz.
3. The wavelength of a photon is 3000 A. The energy of the photon is ___________
a) 3.47 eV
b) 4.54 eV
c) 6.78 eV
d) 2.12 eV
Explanation: We know, E = hc/λ
= 6.6 X 10-34 X 3 X 108/3 X 10-7
= 6.6 X 10-19
= 3.47 eV.
4. An electron makes a transition from n = 5 state to n = 2 state in the hydrogen atom. What is the frequency of the emitted photon?
a) 4.9 X 1014 Hz
b) 5.9 X 1014 Hz
c) 6.9 X 1014 Hz
d) 7.9 X 1014 Hz
Explanation: The electron makes a transition from n = 5 to n = 2.
ΔE=R\((\frac{1}{n_1^2} – \frac{1}{n_2^2})\)
= 45.774 X 10-20J
Frequency, v = ΔE/h
= 6.9 X 1014 Hz.
5. Klystron valve and Magnetron valve are used for the production of ___________
a) Radio Waves
b) Micro Waves
c) Infra-red
d) Ultraviolet
Explanation: Microwaves are also called short-wavelength radio waves. They are produced by special vacuum tubes called klystron valve, magnetron valves, and Gunn diodes. They are used in the radar system as they have a short wavelength
6. Photons are electrically neutral and are not deflected by electric and magnetic fields.
a) True
b) False
Explanation: Photons are considered to have no charge. They are simply quanta of energy. They are not affected by the presence of the electric and magnetic fields
7. In holographic data storage, the information is stored in ______________
a) Pendrives
b) Cells
c) Crystals
d) Diode
Explanation: Holography is used in holographic data storage. In this method, all the data is stored in crystals or photopolymers. It is mostly used in electronic data storage devices.
8. The technique by which image is obtained from a hologram is called as ____________
a) Formation
b) Construction
c) Reconstruction
d) Projection
Explanation: The process of generation of an image from a hologram is called reconstruction. In the process, a wave called reconstruction wave illuminates the hologram, thus giving rise to the desired image.
9. Which of the following is used for the formation of holograms?
a) X-ray
b) Visible Light
c) Infrared
d) Lasers
Explanation: Laser is highly coherent. Due to this, they are widely used in the reconstruction process. In a hologram, each point contains light from the whole of the original scene
10. It is not possible to break a hologram in small pieces.
a) True
b) False
Explanation: Holograms can be broken into smaller pieces and they can be reconstructed to form the entire object. However, the size of the hologram is reduced, as the resolution decreases. The image starts to get blurred.