Current Electricity Charging Discharging Of Capacitors Question 409
Question: Masses of 3 wires of same metal are in the ratio 1 : 2 : 3 and their lengths are in the ratio 3 : 2 : 1. The electrical resistances are in ratio
[CPMT 2002]
Options:
A) 1 : 4 : 9
B) 9 : 4 : 1
C) 1 : 2 : 3
D) 27 : 6 : 1
Show Answer
Answer:
Correct Answer: D
Solution:
$ R\propto \frac{l^{2}}{m}\Rightarrow R _{1}:R _{2}:R _{3}=\frac{l _{1}^{2}}{m _{1}}:\frac{l _{2}^{2}}{m _{2}}:\frac{l _{3}^{2}}{m _{3}} $
$ \Rightarrow ,R _{1}:R _{2}:R _{3}=\frac{9}{1}:\frac{4}{2}:\frac{1}{3}=27:6:1 $ .
BETA
