Current Electricity Charging Discharging Of Capacitors Question 401
Question: A nichrome wire 50 cm long and one square millimetre cross-section carries a current of 4A when connected to a 2V battery. The resistivity of nichrome wire in ohm metre is
[EAMCET 2001]
Options:
A) 1 × $ {{10}^{-6}} $
B) 4 × $ {{10}^{-7}} $
C) 3 × $ {{10}^{-7}} $
D) 2 × $ {{10}^{-7}} $
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Answer:
Correct Answer: A
Solution:
$ R=\frac{V}{i}=\rho \frac{l}{A} $
Therefore $ \frac{2}{4}=\rho \frac{50\times {{10}^{-2}}}{{{(1\times {{10}^{-3}})}^{2}}} $
Therefore $ \rho =1\times {{10}^{-6}}\Omega m $ .
BETA
