MCQ
Magnetic field can be defined as the:
- ASpace surrounding the magnet in which magnetic force acts.
- BSpace surrounding the magnet in which electric force acts.
- CSpace surrounding the magnet in which no force acts.
- DNone.
Explanation:
A magnetic field is generated when electric charge carriers such as electrons move through space or within an electrical conductor. It is the space surrounding the magnet in which magnetic force acts. Its intensity is represented by magnetic lines of force.
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A heating coil is labelled 100 W, 220 V. The coil is cut in half and the two pieces are joined in parallel to the same source. The energy now liberated per second is
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(a) 200 J |
(b) 400 J |
(c) 25 J |
(d) 50 J |
A hollow metal sphere of radius 5cm is charged such that the potential on its surface is 10V. The potential at a distance of 2cm from the centre of the sphere
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(a) Zero |
(b) 10 V |
(c) 4 V |
(d) 10/3 V |
Two coherent light sources S1 and S2 (l= 6000 Å) are 1mm apart from each other. The screen is placed at a distance of 25 cm from the sources. The width of the fringes on the screen should be
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(a) 0.015 cm |
(b) 0.025 cm |
(c) 0.010 cm |
(d) 0.030 cm |
A passenger in an aeroplane shall:
Two wires A and B of same material and mass have their lengths in the ratio 1 : 2. On connecting them to the same source, the rate of heat dissipation in B is found to be 5W. The rate of heat dissipation in A is
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(a) 10W |
(b) 5W |
(c) 20W |
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