A potential difference of 220 V is applied across a rheostat of 12000 Ω . The voltmeter V has a resistance of 6000 Ω and distance BC is one-fourth of the distance from A to B . The error in the reading of voltmeter is approximately -

Step-by-step solution

It total voltage across A B is 220 then voltage across C B should be 220 4 = 55 V (voltage to be measured) V ′ = 220 × 2000 11000 = 40 V (voltage being measured) ∴ % e r r o r = V - V ′ V × 100 = 55 - 40 55 × 100 =27%