1
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If a source of power 4 kW produces 10^20 photons/second

If a source of power 4 kW produces 10^{20} photons/second, the radiation belongs to a part of the spectrum called

- microwaves
- X rays
- γ rays
- ultraviolet rays

2
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An electromagnetic wave of frequency v = 3.0 MHz passes

An electromagnetic wave of frequency v = 3.0 MHz passes from vacuum into a dielectric medium with permittivity ∈ = 4.0. Then

- wave length is double and frequency becomes half
- wave length is double and the frequency remains unchanged
- wave length is halved and frequency remains unchanged
- wave length and frequency both remain unchanged

3
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Infra red radiation is detected by

Infra red radiation is detected by

- photometer
- nanometer
- spectrometer
- pyrometer

4
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Arrange the following electromagnetic radiations per quantum in the order of increasing energy

Arrange the following electromagnetic radiations per quantum in the order of increasing energy:

A: Blue light; B: Yellow light; C: X-ray; D: Radio wave

- A, B, D, C
- C, A, B, D
- B, A, D, C
- D, B, A, C

Consider the graph in which the birthrate and death rate of a country
A wholesaler bought walnuts and peanuts, the price of walnut per kg being thrice
Each of 74 students in a class studies at least one of the three subjects
Which frequency range is sensitive to human ears
Train T leaves station X for station Y at 3 pm
log12 81 = p, then 3[(4-p)/(4+p)] is equal to
A right circular cone, of height 12 ft, stands on its base
Points E, F, G, H lie on the sides AB, BC, CD, and DA