engineering physics MCQ #983

A cell of emf E and internal resistance r is connected across a variable resistor R. The maximum power dissipated in R is?

engineering physics MCQ #983

  1. Question 1

    Q1. A cell of emf E and internal resistance r is connected across a variable resistor R. The maximum power dissipated in R is?

    • A) E² / r
    • B) E² / 4r
    • C) E² / R
    • D) E² / 4R

    Answer: E² / 4r

    Explanation: Maximum power is dissipated when R = r, P_max = E² / 4r.