Force between two identical bar magnets whose centres are r metre apart is 4.8 N, when their axes are in the same line. If separation is increased to 2r, the force between them is reduced to
|
(a) 2.4N |
(b) 1.2N |
(c) 0.6N |
(d) 0.3N |
(d) 0.3N
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The Lyman series of hydrogen spectrum lies in the region
|
(a) Infrared |
(b) Visible |
(c) Ultraviolet |
(d) Of X - rays |
Assertion : The earth’s magnetic field does not affect the working of a moving coil galvanometer.
Reason : Earth’s magnetic field is very weak.
|
(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 magnetic moment of atomic neon is
| (a) Zero | (b) μB/2 | (c) μB | (d) 3μB/2 |
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
|
(a) AB |
(b) CD |
|
(c) Segment OB only of line AB |
(d) Segment OC only of line CD |
The current in a coil of inductance 5 H decreases at the rate of 2 A/s. The induced e.m.f. is
|
(a) 2 V |
(b) 5 V |
(c) 10 V |
(d) – 10 V |