Current Electricity Charging Discharging Of Capacitors Question 121
Question: The same mass of copper is drawn into two wires 1 mm and 2 mm thick. Two wires are connected in series and current is passed through them. Heat produced in the wire is in the ratio
Options:
A) 2 : 1
B) 1 : 16
C) 4 : 1
D) 16 : 1
Show Answer
Answer:
Correct Answer: D
Solution:
$ H=i^{2}RT=i^{2}( \frac{\rho l}{A} ),t=\frac{i^{2}\rho Vt}{A^{2}} $ (V = volume, = Al)
Therefore $ H\propto \frac{1}{r^{4}} $
Therefore $ \frac{H _{1}}{H _{2}}={{( \frac{r _{2}}{r _{1}} )}^{4}}={{( \frac{2}{1} )}^{4}}=\frac{16}{1} $ .
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