Question

In order to measure temperature across a tank $Cu-Cn\left(10\mu V{/}^{\circ }C\right)$ and $In-Cn\left(20\mu V{/}^{\circ }C\right)$ are attached alternatively as shown below. A Voltmeter is attached to measure the voltage. The reading of the Voltmeter is

• A. $130\mu V$
• B. $230\mu V$
• C. $430\mu V$
• D. $330\mu V$

Answer 1

The correct option is D $330\mu V$

Let V be the reading of voltmeter.

Apply KVL in the loop of voltmeter,

$\Rightarrow V-T_1\times S_{(cu-cn)}-T_2\times S_{(In-cn)}-T_3\times S_{(cu-cn)}-T_4\times S_{(In-cn)}-T_5\times S_{(cu-cn)}-T_6\times S_{(In-cn)}=0$

$\Rightarrow V-1^{o}C\times 10\mu V{/}^{o}C-2^{o}C\times 20\mu V{/}^{o}C-3^{o}C\times 10\mu V{/}^{o}C-4^{o}C\times 20\mu V{/}^{o}C-5^{o}C\times 10\mu V{/}^{o}C-6^{o}C\times 20\mu V{/}^{o}C=0$

$\Rightarrow V=330\mu V$