ExamBro
ExamBro
TS EAMCET · Maths · Application of Derivatives

Electric current (I) is measured by galvanometer, the current being proportional to the tangent of the angle \((\theta)\) of deflection. If the deflection is read as \(45^{\circ}\) and an error of \(1 \%\) is made in reading it, the percentage error in the current is

  1. A \(\pi\)
  2. B \(\frac{\pi}{2}\)
  3. C \(\frac{\pi}{3}\)
  4. D \(\frac{\pi}{4}\)
Verified Solution

Answer & Solution

Correct Answer

(B) \(\frac{\pi}{2}\)

Step-by-step Solution

Detailed explanation

\begin{aligned} & \quad I \propto \tan \theta \\ & d I=\sec ^2 \theta d \theta \\ & \frac{\Delta I}{I} \times 100=\sec ^2 \theta \frac{\Delta \theta}{\theta} \times 100 \\ & \text { when } \theta=\frac{\pi}{4} \\ & \frac{\Delta \theta}{\theta} \times 100=\frac{\pi}{4} \times…