71. The value of energy quantum for radiation of any frequency is proportional to :
A. the frequency
B. the reciprocal of the energy
C. the square of the frequency
D. the square root of the frequency
72. The emission of electrons from a metal plate exposed to light depends on the :
A. intensity of the light
B. frequency of light
C. both (a) and (b)
D. neither (a) nor (b)
73. Assuming n as the frequency of radiation, no as the threshold frequency and k as a constant, the energy of the photo-electrons (E) is related as
A. E = k (n - no)
B. E = k (n + no)
C. E = k (a x no)
D. E = (n. + no)
74. Which one of the following can travel through empty space :
A. sound waves
B. water waves
C. electromagnetic waves
D. spring waves
75. 'A time varying magnetic field produces an electric field'. This phenomenon is known as
A. Newton's law
B. Kirchoff law
C. Ampere Maxwell law
D. Faraday's law
76. 'A time varrying electric field produces a magnetic field.' This phenemenon is called:
A. Hertz's law
B. Ampere Maxwell's law
C. Faraday's law
D. Kirchoffs law
77. The reflection of solar energy is characterised by the water content in the leaf, in the reflective optical infrared :
A. visible (0.4 ? 0.7 gm) region
B. near-IR (0.7 ? 1.3 gm) region
C. short wave-IR (1.3 ?2.7 gm) region
D. None of these
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