Zener Diode as Voltage Stabilizer

Q. A zener diode of power rating \(2~\text W\) is to be used as a voltage regulator. If the zener diode has a breakdown of \(10~\text V\) and it has to regulate voltage fluctuated between \(6~\text V\) and \(14~\text V, \) the value of \(R_{S}\) for safe operation should be ________\(\Omega .\)


Ry —AMW—T————o Unregulate Regulated voltage voltage o 

Q. The avalanche breakdown in p-n junction is due to

1. shift of Fermi level.
2. high impurity concentration.
3. widening of forbidden gap.
4. cumulative effect of conduction band electron.

Q. Which of the following is/are true regarding breakdown voltage of Zener diode?

1. The holes in the n-side and the conduction electrons in the p-side are accelerated due to the reverse bias voltage.
2. If the reverse bias voltage across a p-n junction diode is increased, at a particular voltage the reverse current suddenly decreases to a large value
3. The voltage at which the rate of creation of hole-electron pairs is increased leading to the increased current is called avalanche breakdown
4. None of the above

Q. What happens during regulation action of Zener diode?

1. The current in and voltage across the Zener remains fixed
2. The current through the series Resistance ($R_s$) changes
3. The Zener resistance is constant
4. The resistance offered by the Zener diode changes

Q. Zener diode is used as ......................

Q. How is Zener diode used as voltage regulator?

Q. A zener diode can be used as

1. oscillator .
2. voltage regulator.
3. rectifier.
4. transformer.

Q. The current flowing through the zener diode in figure is:

1. $20mA$
2. $25mA$
3. $15mA$
4. $5mA$

Q. What is the value of output voltage $v_0$ in the circuit shown in the figure

1. 6V
2. 15V
3. 20V
4. 26V

Q. If, a Zener diode ($V_z=5V$ and $I_z=10mA$) is connected in series with a resistance and 20 V is applied across the combination, then the maximum resistance one can use without spoiling zener action is

1. 20 $k\Omega$
2. 15 $k\Omega$
3. 10 $k\Omega$
4. 1.5 $k\Omega$