P-type semiconductors are made by adding impurity element
|
(a) As |
(b) P |
(c) B |
(d) Bi |
P-type semiconductors are made by adding impurity element
|
(a) As |
(b) P |
(c) B |
(d) Bi |
(c) B
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A positively charged thin metal ring of radius R is fixed in the xy - plane with its centre at the O. A negatively charged particle P is released from rest at the point (0, 0, where
. Then the motion of P is
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(a) Periodic for all values of |
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(b) Simple harmonic for all values of satisfying 0 < |
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(c) Approximately simple harmonic provided |
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(d) a, c |
A beam of plane polarized light falls normally on a polarizer of cross sectional area 3 . Flux of energy of incident ray in 10–3 W. The polarizer rotates with an angular frequency of 31.4 rad/sec. The energy of light passing through the polarizer per revolution will be
|
(a) 10–4 Joule |
(b) 10–3 Joule |
(c) 10–2 Joule |
(d) 10–1 Joule |
A photo cell is receiving light from a source placed at a distance of 1 m. If the same source is to be placed at a distance of 2 m, then the ejected electron
|
(a) Moves with one-fourth energy as that of the initial energy |
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(b) Moves with one-fourth of momentum as that of the initial momentum |
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(c) Will be half in number |
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(d) Will be one-fourth in number |
Which of the following graphs shows the variation of magnetic induction B with distance r from a long wire carrying current
|
(a)
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(b)
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(c)
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(d)
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A wire in the form of a circular loop of one turn carrying a current produces a magnetic field B at the centre. If the same wire is looped into a coil of two turns and carries the same current, the new value of magnetic induction at the centre is
|
(a) 5B |
(b) 3B |
(c) 2B |
(d) 4B |
Light waves can be polarised as they are
|
(a) Transverse |
(b) Of high frequency |
(c) Longitudinal |
(d) Reflected |
If a bar magnet of magnetic moment M is freely suspended in a uniform magnetic field of strength B, the work done in rotating the magnet through an angle θ is
|
(a) MB(1- sinθ |
(b) MB sinθ |
(c) MB cosθ |
(d) MB(1 – cosθ) |
A square loop of side 5 cm enters a magnetic field with 1 cms-1. The front edge enters the magnetic field at t = 0 then which graph best depicts emf

(a)
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(b)
|
(c)
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(d)
|