(a) Three resistors R_1, R_2 and R_3 are connected in parallel and the combination is connected to a battery, an ammeter, a voltmeter and a key. Draw…

(a) Circuit diagram with given components Direction

(b) Resistance between \(\displaystyle C\) and \(\displaystyle D\) is given by \[\begin{aligned} & \frac{1}{R_{C D}}=\frac{1}{10}+\frac{1}{10}=\frac{2}{10}=\frac{1}{5} \\ & R_{C D}=5 \Omega \end{aligned} \] \[D \text { and } B=R_{4}=5 \Omega \] ∴ Total resistance is \(\displaystyle \mathrm{R}_{\mathrm{S}}=\mathrm{R}_{\mathrm{CD}}+\mathrm{R}_{1}+\mathrm{R}_{4}\) \[\begin{aligned} R_{\text {total }} & =5 \Omega+5 \Omega+5 \Omega \\ & =15 \Omega \end{aligned} \]