In a forward biased p-n junction diode, the potential barrier in the depletion region is of the form
If the forward voltage in a diode is increased, the width of the depletion region
increases
decreases
fluctuates
no change
B.
decreases
On increasing the forward bias voltage, the barrier energy decreases. This results in the flow of majority charge carriers.Hence, width of depletion region decreases.
Four metal conductors having different shape
are mounted on insulating stands and charged. The one which is best suited to retain the charges for a longer time is
1
2
3
4
The potential to which a conductor is raised, depends on
the amount of charge
geometry and size of the conductor
Both (a) and (b)
only on (a)
Identify the property which is not characteristic for a semiconductor ?
At a very low temperatures, it behaves like a insulator
At higher temperatures two types of charge carriers will cause conductivity
The charge carriers are electrons and holes in the valence band at higher temperatures
The semiconductor is electrically neutral
In a transistor the collector current is always less than the emitter current because
collector side is reverse biased and the emitter side is forward biased
a few electrons are lost in the base and only remaining ones reach the collector
collector being reverse biased, attracts less electrons
collector side is forward biased and emitter side is reverse biased
To a germanium crystal equal number of aluminium and indium atoms are added. Then
it remains an intrinsic semiconductor
it becomes a n-type semiconductor
it becomes a p-type semiconductor
it becomes an insulator
Minority carriers in a p-type semiconductor are
free electrons
holes
neither holes nor free electrons
both holes and free electrons
In a reverse biased diode when the applied voltage changes by 1 V, the current is found to change by 0.5 µA. The reverse bias resistance of the diode is
2 × 105 Ω
2 × 106 Ω
200 Ω
2 Ω