ExamBro
ExamBro
JEE Mains · Physics · STD 12 - Current electricity
  • JEE Mains 2024
  • Hard
  • MCQ

By what percentage will the illumination of the lamp decrease if the current drops by \(20 \%\) ?

Pick an option to check your answer.
Verified Solution

Answer & Solution

Correct Answer

(C) \(36 \%\)

Step-by-step Solution

Detailed explanation

\(P=i^2 R\)

\(P_{\text {int }}=I^2{ }_{\text {int }} R\)

\(P_{\text {final }}=\left(0.8 I_{\text {int }}\right)^2 R\)

\(\% \text { change in power }=\)

\(\frac{P_{\text {final }}-P_{\text {int }}}{P_{\text {int }}} \times 100=(0.64-1) \times 100=-36 \%\)

Same subject
Explore more questions on app