A Zener diode has Zener voltage 10 V and maximum permissible power dissipation 0.5 W. It is connected to a 25 V supply through a series resistor. If the minimum safe value of the resistor is N Ω, find N.
Physics · semiconductor · application of diode and zener breakdown
JEE Mains 2026 4 April Evening Shift

Question

A Zener diode has Zener voltage 10 V and maximum permissible power dissipation 0.5 W. It is connected to a 25 V supply through a series resistor. If the minimum safe value of the resistor is N Ω, find N.

Physics · semiconductor · application of diode and zener breakdown

JEE Mains 2026 4 April Evening Shift

G1 Physics · Accepted Answer

The maximum safe Zener current is determined from P(max) = V(Z)I(max). Therefore, I(max) = 0.5 ÷ 10 = 0.05 A. The series resistor must drop the remaining voltage: V(R) = 25-10 = 15 V. For the maximum safe current, R(min) = V(R) ÷ I(max) = 15 ÷ 0.05 = 300 Ω. Therefore N = 300.