A cathode emits 1.8 
electrons per second, when heated. When 400V is applied to anode all the emitted electrons reach the anode. The charge on electron is 1.6 
. The maximum anode current is
|
(a) 2.7 μA |
(b) 29 μA |
(c) 72 μA |
(d) 29 μA |
(b) 29 μA
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Light of wavelength is 700 Å in air. It has a wavelength in glass (μ = 1.5) equal to
|
(a) 7200 Å |
(b) 4800 Å |
(c) 10800 Å |
(d) 7201.5 Å |
When a light wave goes from air into water, the quality that remains unchanged is its
|
(a) Speed |
(b) Amplitude |
(c) Frequency |
(d) Wavelength |
In a circuit 5 percent of total current passes through a galvanometer. If resistance of the galvanometer is G then value of the shunt is
|
(a) 19 G |
(b) 20 G |
(c) |
(d) |
A heavy nucleus at rest breaks into two fragments which fly off with velocities in the ratio 8 : 1. The ratio of radii of the fragments is
|
(a) 1 : 2 |
(b) 1 : 4 |
(c) 4 : 1 |
(d) 2 : 1 |
Nuclear fusion is common to the pair
| (a) Thermonuclear reactor, uranium based nuclear reactor |
| (b) Energy production in sun, uranium based nuclear reactor |
| (c) Energy production in sun, hydrogen bomb |
| (d) Disintegration of heavy nuclei, hydrogen bomb |
The half-life of radon is 3.8 days. Three forth of a radon sample decay in
|
(a) 5.02 days |
(b) 15.2 days |
(c) 7.6 days |
(d) 11.4 days |
A coil of 100 turns and area 5 square centimetre is placed in a magnetic field B = 0.2 T. The normal to the plane of the coil makes an angle of 60° with the direction of the magnetic field. The magnetic flux linked with the coil is
|
(a) 5 |
(b) 5 |
(c) |
(d) |
