Measurements and Instrumentation - Engineering

Q1:

An ammeter has a resistance of 50 ohms and a shunt of 0.01 Ω. The deflection is θ. If the shunt resistance is increased to 0.02 Ω, the deflection will be.

A θ

B

C 0.5θ

D 0.25θ

ANS:B - 2θ

Since shunt resistance is doubled, current through ammeter is doubled (current division for resistances in parallel). Therefore reading is 2 θ.