Current Electricity Charging Discharging Of Capacitors Question 258
Question: A potentiometer wire of length $ 1,m $ and resistance 10 W is connected in series with a cell of emf 2V with internal resistance 1 W and a resistance box including a resistance R. If potential difference between the ends of the wire is 1 mV, the value of R is
[KCET 1999]
Options:
A) 20000 W
B) 19989 W
C) 10000 W
D) 9989 W
Show Answer
Answer:
Correct Answer: B
Solution:
$ V=i.R\text{. }=\frac{e}{(R+R _{h}+r)},.,R\Rightarrow {{10}^{-3}}=\frac{2}{(10+R+r)}\times 10 $
$ \Rightarrow R=19,989\Omega $ .
BETA
