Zener Diode

Q. A Zener diode, having breakdown voltage equal to $15V$, is used in a voltage regulator circuit shown in figure. The current through the diode is:

1. $5mA$
2. $10mA$
3. $15mA$
4. $20mA$

Q.

Two Zener diodes (A and B) having breakdown voltages of $ 6V$ and $ 4V$ respectively, are connected as shown in the circuit below. The output voltage $ {V}_{O}$ variation with input voltage linearly increasing with time is given by $ \left({V}_{input}=0V at t=0\right)$ (figures are qualitative).

Q. A Zener diode:

1. is a battery.
2. has a constant voltage in the breakdown region.
3. has a barrier potential of 1 V.
4. is forward biased.

Q. Five capacitors are connected as shown in the figure. Initially, all capacitors are uncharged and $S$ is open. When $S$ is closed, then the potential difference between points $\text{M}$ and $\text{N}$ is :
[assume steady state to be achieved after $S$ closes]

1. $15\text{V}$
2. $10\text{V}$
3. $14\text{V}$
4. $12\text{V}$

Q.
A Zener diode of 5 V with a load current of $4mA$ is used. What should be the value of $R^{}$?

1. 3.0 $k\Omega$
2. 2.5 $k\Omega$
3. 4.0 $k\Omega$
4. 3.6 $k\Omega$

Q.
A Zener diode of 5 V with a load current of $4mA$ is used. What should be the value of $R^{}$?

1. 3.0 $k\Omega$
2. 2.5 $k\Omega$
3. 4.0 $k\Omega$
4. 3.6 $k\Omega$

Q. A battery having emf $E_1=100\text{V}$ and internal resistance $r=0.5\Omega$ is connected to a storage battery of emf $E_2=90\text{V}$ and external resistance $R$ as shown in figure. For what value of $R$ no current will pass through storage battery $E_2$?

1. $7.5\Omega$
2. $4.5\Omega$
3. $2.5\Omega$
4. $5.5\Omega$

Q.

In the circuit shown, A and B represent two inputs and C represents the output. The circuit represents

1. NAND gate

2. OR gate

3. NOR gate

4. AND gate