An electron of mass m when accelerated through a potential difference V has de-Broglie wavelength λ. The de-Broglie wavelength associated with a proton of mass M accelerated through the same potential difference will be
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(a) λ |
(b) λ |
(c) λ |
(d) λ |
(b) λ
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A circular coil of mean radius of 7 cm and having 4000 turns is rotated at the rate of 1800 revolutions per minute in the earth's magnetic field (B = 0.5 gauss), the maximum e.m.f. induced in coil will be
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(a) 1.158 V |
(b) 0.58 V |
(c) 0.29 V |
(d) 5.8 V |
The focal length of a convex mirror is 20 cm its radius of curvature will be
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(a) 10 cm |
(b) 20 cm |
(c) 30 cm |
(d) 40 cm |
In double slits experiment, for light of which colour the fringe width will be minimum
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(a) Violet |
(b) Red |
(c) Green |
(d) Yellow |
Half life of a radio-active substance is 20 minutes. The time between 20% and 80% decay will be
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(a) 20 minutes |
(b) 40 minutes |
(c) 30 minutes |
(d) 25 minutes |
The current in a coil changes from 4 ampere to zero in 0.1 s. If the average e.m.f. induced is 100 volt, what is the self inductance of the coil
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(a) 2.5 H |
(b) 25 H |
(c) 400 H |
(d) 40 H |
Given below are four logic gate symbol (figure). Those for OR, NOR and NAND are respectively
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(a) 1, 4, 3 |
(b) 4, 1, 2 |
(c) 1, 3, 4 |
(d) 4, 2, 1 |
Assertion : Short wave bands are used for transmission of radio waves to a large distance.
Reason : Short waves are reflected by ionosphere
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(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. |
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(c) If assertion is true but reason is false. |
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(d) If the assertion and reason both are false. |
