Current Electricity Charging Discharging Of Capacitors Question 308
Question: In a metre bridge experiment null point is obtained at 20 cm from one end of the wire when resistance X is balanced against another resistance Y. If X < Y, then where will be the new position of the null point from the same end, if one decides to balance a resistance of 4X against Y
[AIEEE 2004]
Options:
A) 50 cm
B) 80 cm
C) 40 cm
D) 70 cm
Show Answer
Answer:
Correct Answer: A
Solution:
In balancing condition, $ \frac{R _{1}}{R _{2}}=\frac{l _{1}}{l _{2}}=\frac{l _{1}}{100-l _{1}} $
Therefore $ \frac{X}{Y}=\frac{20}{80}=\frac{1}{4} $ …..(i) and $ \frac{4X}{Y}=\frac{l}{100-l} $ …..(ii)
Therefore $ \frac{4}{4}=\frac{l}{100-l} $
Therefore $ l=50,cm $
BETA
