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WorksheetsEP-IAT II TEST (23.1.21)
Total questions: 25
Worksheet time: 47mins
1.In stimulated emission process, transition of atom takes place from
a) Higher energy level to lower energy level
b) Lower energy level to higher energy level
c) None of the above
2.Population inversion is the condition in which the no of atoms in
a) Higher energy level is greater than lower energy level
b) Lower energy level is greater than higher energy level
c) Both the higher and lower energy level has equal no. of atoms
3. Optical resonator consists of
a) One partially reflecting mirror and one 100% reflecting mirror.
b) Two 100% reflecting mirrors
c) Two partially reflecting mirrors
4. Laser beam is
a) Highly directional, coherent and monochromatic
b) Highly directional, monochromatic and non coherent
c) Highly directional, polychromatic and coherent
5. One of the conditions for total internal reflection is
a) Refractive index of core must be greater than refractive index of cladding
b) Refractive index of core must be less than refractive index of cladding
c) Refractive index of core and cladding must be equal.
6. The sine of the acceptance angle of the fibre is called as
a) Fractional index change
b) Numerical aperture
c) Critical angle
7. Heat transfer can be reduced by convection, conduction and radiation
a) True
b) False
8. The bimetallic strip bends due to the unequal expansion rate of the two metals.
a) True
b) False
9. The maximum angle at which light can enter through one end of fibre to undergo total internal reflection is
a) Critical angle
b) Acceptance angle
c) Divergence angle
10. Attenuation is measured in terms of
a) dB/km
b) db/m
c)db/cm
11. Homo junction lasers have more divergence than hetero junction lasers.
a) True
b) False
12. The wavelength of light emission from GaAs whose band gap is 1.44eV is
a) 7826
b) 8626
c) 6970
13. 1. Expansion in length of a material, on heating is called as
a) Superficial expansion
b) Cubical expansion
c) Linear expansion
14. Which of the following safely absorb the heat induced expansion or contraction of pipeline?
a) Bimetallic strips
b) I beams
c) Expansion joints
15. The device used to maintain constant temperature is
a) Bimetallic thermometer
b) Bimetallic thermostat
c) Bimetallic sensor
16. Conduction is the process in which there is actual movement of particles during heat transfer
a) True
b) False
17. Amount of heat flowing through a material is directly proportional to
a) Area, temperature difference and time of flow
b) Temperature difference, length between the faces and time of flow
c) Temperature difference, area and length between the faces
18. Forbe’s method is used to determine the conductivity of
a) Bad conductors
b) Good conductors
c) Both good and bad conductors
d) None of the above
19. What are the materials used for thermal insulation?
a) Cattle hair, silk and wool
b) Paper, leather and cardboard
c) Iron, rubber and wax
d) Both a and b
20. The process in which heat is transmitted from one place to another directly, without the agency of any material is called
a) Conduction
b) Convection
c) Radiation
d) conduction, convection, radiation
21. Sunlight contains infrared radiations in all proportion.
a) True
b) False
22. The unit of thermal conductivity is
a) W/m/K
b) WmK
c) W m/K
d) None of the above
23. Optical pumping is the method in which
a) Light radiation is used for excitation of atoms
b) Electrical energy is used for excitation of atoms
c) None of the above
24. What are the characteristics of SHM?
a. Oscillatory
b. Periodic
c. Both a and b
d. None
25.Amplitude is defined as
a. maximum displacement of the particle from the mean position.
b. minimum displacement of the particle from the mean position.
c. average displacement of the particle from the mean position.
d. mean displacement of the particle from the mean position.
