Question

An ammeter, suspected to give inaccurate reading, is connected in series with a silver voltameter. The ammeter indicates. 0.54 A. A steady current passed for one hour deposits 2.0124 gm of silver. If the e.c.e. of silver is $1.118\times {10}^{-3}$ gmC${}^{-1}$, then the error in ammeter reading is

• A. +0.04 A
• B. + 0.02 A
• C. -0.03 A
• D. - 0.01 A

Answer 1

Answer: (A)

+0.04 A

$\text{Use the formula,}m=ZIt$

$\Rightarrow I=\frac{m}{Zt}$

$\text{Actual current}=I=\frac{2.0124}{1.118\times {10}^{-3}}\frac{1}{60\times 60}=0.50A$

$\text{Error}=0.54-0.50=+0.04\text{A}$