The current through choke coil increases form zero to 6A in 0.3 seconds and an induced e.m.f. of 30 V is produced. The inductance of the coil of choke is
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(a) 5 H |
(b) 2.5 H |
(c) 1.5 H |
(d) 2 H |
(c) 1.5 H
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A wire has resistance 12 Ω. It is bent in the form of a circle. The effective resistance between the two points on any diameter is equal to
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(a) 12 Ω |
(b) 6 Ω |
(c) 3 Ω |
(d) 24 Ω |
When light is incident on a diffraction grating the zero order principal maximum will be
|
(a) One of the component colours |
(b) Absent |
|
(c) Spectrum of the colours |
(d) White |
Assertion : The capacity of a given conductor remains same even if charge is varied on it.
Reason : Capacitance depends upon nearly medium as well as size and shape of conductor.
|
(a) If both assertion and reason are true and the reason is the correct explanation of the assertion. |
|
(b) If both assertion and reason are true but reason is not the correct explanation of the assertion. |
|
(c) If assertion is true but reason is false. |
|
(d) If the assertion and reason both are false. |
The radius of curvature of the curved surface of a plano-convex lens is 20cm. If the refractive index of the material of the lens be 1.5, it will.
Angle of prism is A and its one surface is silvered. Light rays falling at an angle of incidence 2A on first surface return back through the same path after suffering reflection at second silvered surface. Refractive index of the material of prism is
|
(a) 2 sin A |
(b) 2 cos A |
(c) |
(d) tan A |
