JEE Main · 2020 · 09 Jan 2020 · Shift 2 · Current Electricity

WhatsApp Email

The circuit as shown in figure is working as a 8 V dc regulated voltage source. When 12 V is used as input, the power dissipated (in mW) in each diode is (considering both zener diodes are identical) ____.

Answer: 40

Solution

The two identical Zener diodes in series clamp the output at

8 V

, so with a

12 V

input the surplus

12 - 8 = 4 V

falls across the series resistance. With the

400 Ω

in the regulating branch the current is

i = \frac{4}{400} = 0.01 A = 10 mA

, and this same current flows through each diode, which holds

4 V

across it. The power dissipated in each diode is therefore

P = V i = 4 \times 0.01 = 0.04 W = 40 mW

JEE Main · 2020 · 09 Jan 2020 · Shift 2 · Integer answer

Practise more: all JEE Main PYQs on Current Electricity →

More JEE Main questions on Current Electricity

A meter bridge with two resistances $R_{1}$ and $R_{2}$ as shown in figure was balanced (null point) at 40 cm from the point P. The null point changed to 50 cm from the point P, when $16Ω$ resistance is connected in parallel to $R_{2}$ . The values of resistances $R_{1}$ and $R_{2}$ ar …
JEE Main 2026View solution →
An electric power line having total resistance of $2Ω$ , delivers 1 kW of power of 250 V. The percentage efficiency of transmission line is $____$ .
JEE Main 2026View solution →
A cylindrical conductor of length 2 m and area of cross-section $0.2 mm^{2}$ carries an electric current of 1.6 A when its ends are connected to a 2 V battery. Mobility of electrons in the conductor is $α \times 1 0^{- 3} m^{2} / V$ .s. The value of …
JEE Main 2026View solution →
The charge stored by the capacitor C in the given circuit in the steady state is $____$ $μ C$ .
JEE Main 2026View solution →
The total length of potentiometer wire AB is 50 cm in the arrangement as shown in figure. If P is the point where the galvanometer shows zero reading then the length AP is $____$ cm .
JEE Main 2026View solution →
A battery with EMF E and internal resistance $r$ is connected across a resistance $R$ . The power consumption in R will be maximum when :
JEE Main 2026View solution →