The conductivity of a semiconductor incr...

The conductivity of a semiconductor increases with increase in temperature because

number density of free current carriers increases

relaxatoin time increses

both number density of carriers and relaxiation time increase

number density of current carriers increases relaxation time decreased but effect of decrease in relaxation time is much less than increase in number density

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With the increase in temperature relaxation time decreases and on the other hand the numbr density of current carriers increases but the effect increases in number denisty

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Assertion (A) : The electrical conductivity of a semiconductor increases with increase in temperature. Reason (R ) : With increase in temperature, large number of electrons from the valence band can jump to the conduction band.

If both `(A)` and `(R)` are correct, and `(R)` is the correct explanation of `(A)`

If both `(A)` and `(R)` are correct, but `(R)` is not the correct explanation of `(A)`

If `(A)` is correct, but `(R)` is incorrect.

If both `(A)` is incorrect, but `(R)` is correct.

Statement 1: Conductivity of semiconductor increases with increase in temperature. Statement 2: Forbidden energy gap is highest for semiconductors.

Both Statement-1 and Statement-2 are true, and Statement-2 is the correct explanation of Statement-1.

Both Statement-1 and Statement-2 are true but Statement-2 is not the correct explanation of Statement -1.

Statement-1 is true but Statement-2 is false.

Statement-1 is false but Statement-2 is true.

Statement 1: Conductivity of semiconductors decreases with increase in temperature Statement-2: More electron goes from valance band to conduction band with increase in temperature.