Zener Diode

Q. An electric bulb rated 100w , 100v has to be operated across 141.4 v , 50hz ac supply . The capacitance of the capacitor which has to connected in series with bulb so that it will glow with full intensity is ?

Q.

In the given circuit, the current through the Zener diode is

1. $2.5mA$

2. $3.3mA$

3. $5.5mA$

4. $6.7mA$

Q. In the case of p-n junction diode at a high value of reverse bias voltage, the current rises sharply. The value of reverse bias voltage is known as

1. cut-off voltage
2. zener voltage
3. inverse voltage
4. critical voltage

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

Q. The ratio of peak value and r.m.s value of an alternating current is

1. 1
2. 1/2
3. √2
4. 1/√2