What is a virtual image?
- AThe image that cannot be caught on a screen.
- BThe image that can be caught on a screen.
- CThe image that cannot be converged on a screen.
- DNone
What is a virtual image?
Explanation:
When the actual rays diverge then they can never meet to form an image. Therefore the rays are assumed to meet in the backward direction of their propagation.
As the imaginary light rays meet and form the image, therefore the image can not be caught on a screen.
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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
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(a) |
(b) |
(c) |
(d) |
Assertion : Base in a transistor is made very thin as compared to collector and emitter regions.
Reason : Due to thin base power gain and voltage gain is obtained by a transistor.
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(a) If both assertion and reason are true and the reason is the correct explanation of the assertion. |
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(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. |
A particle with charge q, moving with a momentum p, enters a uniform magnetic field normally. The magnetic field has magnitude B and is confined to a region of width d, where d < , The particle is deflected by an angle θ in crossing the field
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(a) sinθ = |
(b) sinθ = |
(c) sinθ = |
(d) sinθ = |
The phenomenon of light bending due to change of medium is called:
A hollow metallic sphere of radius R is given a charge Q. Then the potential at the centre is
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(a) Zero |
(b) |
(c) |
(d) |
Refractive index of air is 1.0003. The correct thickness of air column which will have one more wavelength of yellow light (6000 Å) than in the same thickness in vacuum is
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(a) 2 mm |
(b) 2 cm |
(c) 2 m |
(d) 2 km |
If a current is passed in a spring, it
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(a) Gets compressed |
(b) Gets expanded |
(c) Oscillates |
(d) Remains unchanged |