Question 567: Current Electricity

Question

A voltmeter of resistance $$150 \Omega$$ connected across a cell of e.m.f. $$3 \mathrm{~V}$$ reads $$2.5 \mathrm{~V}$$. What is the internal resistance of the cell?

Accepted Answer

Internal resistance,
$$\begin{aligned}
r & =\left[\frac{E}{V}-1ight] R \
& =\left[\frac{3}{2.5}-1ight] 150 \
& =30 \Omega
\end{aligned}$$

Answer

$$10 \Omega$$

Answer

$$15 \Omega$$

Answer

$$20 \Omega$$

Answer

$$30 \Omega$$

Current Electricity

A voltmeter of resistance $150 \Omega connected across a cell of e.m.f. 3 \mathrm{~V} reads 2.5 \mathrm{~V}$. What is the internal resistance of the cell?

Choose the correct answer: