- ADopin
- BBreaking of covalent bonds
- CFree electrons
- DHoles
Explanation:
In intrinsic semiconductors, n = p. Hence, at room temperature, no free electrons are available for conduction.
If some energy is supplied to the atoms of intrinsic semiconductor, the covalent bonds will break and electrons will be freed, each electron will leave behind a hole and capture a new hole the process will continued and charge flows through intrinsic semiconductor.
Thus, in intrinsic semiconductor conductivity is due to breaking of covalent bonds.
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(a) Ic |
(b) |
(c) I/c |
(d) |
If two + 5 D lenses are mounted at some distance apart, the equivalent power will always be negative if the distance is
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(a) Greater than 40 cm |
(b) Equal to 40 cm |
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(c) Equal to 10 cm |
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A beam of electrons is moving with constant velocity in a region having electric and magnetic fields of strength
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(a) 20 |
(b) 40 |
(c) 8 |
(d) 5.5 |
When
ampere current is passed in a tangent galvanometer, there is a deflection of 30° in it. The deflection obtained when 3 amperes current is passed, is
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(a) |
(b) |
(c) |
(d) |
A luminous object is placed at a distance of 30 cm from the convex lens of focal length 20 cm. On the other side of the lens, at what distance from the lens a convex mirror of radius of curvature 10 cm be placed in order to have an upright image of the object coincident with it
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(a) A large number of dark Fraunhofer lines |
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(b) A less number of dark Fraunhofer lines |
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(c) No lines at all |
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(d) All Fraunhofer lines changed into brilliant colours |