Two identical cells send the same current in 2Ω resistance, whether connected in series or in parallel. The internal resistance of the cell should be
|
(a) 1 Ω |
(b) 2 Ω |
(c) |
(d) 2.5 Ω |
(b) 2 Ω
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A rod of length 20 cm is rotating with angular speed of 100 rps in a magnetic field of strength 0.5 T about it’s one end. What is the potential difference between two ends of the rod
|
(a) 2.28 V |
(b) 4.28 V |
(c) 6.28 V |
(d) 2.5 V |
A magnet is made to oscillate with a particular frequency, passing through a coil as shown in figure. The time variation of the magnitude of e.m.f. generated across the coil during one cycle is
(a)
|
(b)
|
(c)
|
(d)
|
A metallic solid sphere is placed in a uniform electric field. The lines of force follow the path(s) shown in figure as
|
(a) 1 |
(b) 2 |
(c) 3 |
(d) 4 |
Eddy currents are used in
|
(a) Induction furnace |
(b) Electromagnetic brakes |
|
(c) Speedometers |
(d) All of these |
The number of wavelengths in the visible spectrum
|
(a) 4000 |
(b) 6000 |
(c) 2000 |
(d) Infinite |
