A round uniform body of radius R, mass M and moment of inertia I rolls down (without slipping) an inclined plane making an angle θ with the horizontal. Then its acceleration is
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A circular disc of radius R is removed from a bigger circular disc of radius 2R such that the circumferences of the discs coincide. The centre of mass of the new disc is α/R from […]
A current I flows along the length of an infinitely long, straight, thin walled pipe. Then
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(a) the magnetic field at all points inside the pipe is the same, but not zero […]
The half-life period of a radio-active element X is same as the mean life time of another radio-active element Y. Initially they have the same number of atoms. Then
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(a) X and […]
In gamma ray emission from a nucleus
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(a) only the proton number changes (b) both the neutron number and the proton number change (c) there is no change in the proton number […]
A Carnot engine, having an efficiency of η=1/10 as heat engine, is used as a refrigerator. If the work done on the system is 10J, the amount of energy absorbed from the reservoir at lower […]
A parallel plate condenser with a dielectric of dielectric constant K between the plates has a capacity C and is charges to a potential V volt. The dielectric slab is slowly removed from between the […]
An electric charge 10⁻³ μC is placed at the origin (0,0) of X-Y co-ordinate system. Two points A and B are situated at (√2,√2) and (2,0) respectively. The potential difference between the points A and […]
Carbon,silicon and germanium have four valence electrons each. At room temperature which one of the following statements is most appropriate?
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(a) The number of free electrons for conduction is significant only in […]
Photon of frequency ν has a momentum associated with it. If c is the velocity of light, the momentum is
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(a) hν/c (b) ν/c (c) hνc (d) hνc²
Correct Answer:
hν/c
Explanation: […]
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