Current Electricity Charging Discharging Of Capacitors Question 403
Question: If a wire of resistance R is melted and recasted to half of its length, then the new resistance of the wire will be
[KCET (Med.) 2001]
Options:
R/4
R/2
R
2R
Show Answer
Answer:
Correct Answer: A
Solution:
$ R\propto l^{2}\Rightarrow \frac{R _{1}}{R _{2}}={{( \frac{l _{1}}{l _{2}} )}^{2}} $
$ \Rightarrow ,\frac{R}{R _{2}}={{( \frac{l}{l/2} )}^{2}}=4\Rightarrow R _{2}=\frac{R}{4} $ .
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