A cell of emf 90 V is connected across series combination of two resistors each of $100 \Omega$ resi

Question

A cell of emf 90 V is connected across series combination of two resistors each of $100 \Omega$ resistance. A voltmeter of resistance $400 \Omega$ is used to measure the potential difference across each resistor. The reading of the voltmeter will be

Professor PC Thomas Classes · Answer

Voltmeter in parallel with $100\Omega$: $R_p = \frac{400 	imes 100}{500} = 80\Omega$. Total resistance $= 100 + 80 = 180\Omega$. Voltage across $R_p = 90 	imes \frac{80}{180} = 40 	ext{ V}$.