# Electronics and Communication Engineering - Electronic Devices and Circuits

46.
A p-n junction diode has
low forward and high reverse resistance
a non-linear v-i characteristics
zero forward current till the forward voltage reaches cut in value
all of the above
Explanation:

A p-n Junction has all these features.

47.
Which of the following is true as regards photo emission?
Velocity of emitted electrons is dependent on light intensity
Rate of photo emission is inversely proportional to light intensity
Maximum velocity of electron increases with decreasing wave length
Both holes and electrons are produced
Explanation:

As wavelength decreases, frequency increases and maximum velocity of electron increases.

48.
The power dissipation in a transistor is the product of
emitter current and emitter to base voltage
emitter current and collector to emitter voltage
collector current and collector to emitter voltage
none of the above
Explanation:

Maximum power dissipation occurs at collector junction.

49.
The normal operation of JFET is
constant voltage region
constant current region
both constant voltage and constant current regions
either constant voltage or constant current region
Explanation:

In major portion of drain characteristics ID is constant.

50.
The minority carrier life time and diffusion constant in a semiconductor material are respectively 100 microsecond and 100 cm2/sec. The diffusion length is
0.1 cm
0.01 cm
0.0141 cm
1 cm