Q. An ammeter reads upto 1A. Its internal resistance is 0.81$\Omega$. To increase the range to 10A the value of the required shunt is
A) 0.03$\Omega$
B) 0.3$\Omega$
C) 0.9$\Omega$
D) 0.09$\Omega$
Explanation
(d) To increase the range of ammeter we have to connect a small resistance in parallel
(shunt), let its value be R.
Apply KCL at junction to divide the current.
Voltage across R= Voltage across ammeter
$\Longrightarrow$ $9R = \ 0.81\ \times \ 1$
$\Longrightarrow \ \ \ \ R = \frac{0.81}{9} = 0.09\Omega$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.