Question

A moving coil ammeter has a uniform scale with 50 divisions and gives a full scale reading of 10 A. The instrument can read up to (1/5)th of a scale division with a fair degree of certainity. The resolution of the instrument (in mA) is _____.

• A. 0.4
• B. 4
• C. 0.04
• D. 40

Answer 1

The correct option is D 40

Resolution = Minimum current read by ammeter

$\because 1Scaledivision=\frac{10}{50}\times 1000=200mA$

$\therefore Resolution={\left(\frac{1}{5}\right)}^{th}ofascaledivision$

$=\frac{1}{5}\times 200=40mA$