Current Electricity Charging Discharging Of Capacitors Question 317
Question: Potentiometer wire of length 1 m is connected in series with 490 $ \Omega $ resistance and 2V battery. If 0.2 mV/cm is the potential gradient, then resistance of the potentiometer wire is
[DCE 2005]
Options:
A) 4.9 $ \Omega $
B) 7.9 $ \Omega $
C) 5.9 $ \Omega $
D) 6.9 $ \Omega $
Show Answer
Answer:
Correct Answer: A
Solution:
Potential gradient $ x=\frac{e}{(R+R _{h}+r)}.\frac{R}{L} $
Therefore $ \frac{0.2\times {{10}^{-3}}}{{{10}^{-2}}}=\frac{2}{(R+490+0)}\times \frac{R}{1} $
Therefore R = 4.9 W.
BETA
