Current Electricity Charging Discharging Of Capacitors Question 247
Question: A potentiometer wire has length 10 m and resistance $ 20,\Omega $ . A 2. 5 V battery of negligible internal resistance is connected across the wire with an $ 80,\Omega $ series resistance. The potential gradient on the wire will be
[KCET 1994]
Options:
A) $ 5\times {{10}^{-5}},V/mm $
B) $ 2.5\times {{10}^{-4}},V/cm $
C) $ 0.62\times {{10}^{-4}},V/mm $
D) $ 1\times {{10}^{-5}},V/mm $
Show Answer
Answer:
Correct Answer: A
Solution:
Potential gradient $ x=\frac{e}{(R+R _{h}+r)}\cdot \frac{R}{L} $
Therefore $ x=\frac{2.5}{(20+80+0)}\times \frac{20}{10}=5\times {{10}^{-5}}\frac{V}{mm} $