Two very thin metallic wires placed along X and Y-axis carry equal currents as shown here. AB and CD are lines at 45° with the axes with origin of axes at O. The magnetic field will be zero on the line
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(a) AB |
(b) CD |
|
(c) Segment OB only of line AB |
(d) Segment OC only of line CD |
(a) AB
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Two particles each of mass m and charge q are attached to the two ends of a light rigid rod of length 2R. The rod is rotated at constant angular speed about a perpendicular axis passing through its centre. The ratio of the magnitudes of the magnetic moment of the system and its angular momentum about the centre of the rod is
|
(a) |
(b) |
(c) |
(d) |
Penetrating power of X-rays can be increased by
|
(a) Increasing the potential difference between anode and cathode |
|
(b) Decreasing the potential difference between anode and cathode |
| (c) Increasing the cathode filament current |
|
(d) Decreasing the cathode filament current |
The lead wires should have
|
(a) Larger diameter and low resistance |
|
(b) Smaller diameter and high resistance |
|
(c) Smaller diameter and low resistance |
|
(d) Larger diameter and high resistance |
Assertion : Electron has higher mobility than hole in a semiconductor.
Reason : Mass of electron is less than the mass of hole.
|
(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. |
A crystal diode is a
|
(a) Non-linear device |
(b) Amplifying device |
(c) Linear device |
(d) Fluctuating device |
When the current i is flowing through a conductor, the drift velocity is v. If 2i current is flowed through the same metal but having double the area of cross-section, then the drift velocity will be
|
(a) v/4 |
(b) v/2 |
(c) v |
(d) 4v |
