Current Electricity Charging Discharging Of Capacitors Question 326
Question: The temperature coefficient of resistance for a wire is $ 0.00125/{}^\circ C $ . At 300K its resistance is 1 ohm. The temperature at which the resistance becomes 2 ohm is
[IIT 1980; MP PET 2002; KCET 2003; MP PMT 2001; Orissa JEE 2002]
Options:
A) 1154 K
B) 1100 K
C) 1400 K
D) 1127 K
Show Answer
Answer:
Correct Answer: D
Solution:
$ \frac{{\rho _{1}}}{{\rho _{2}}}=\frac{(1+\alpha t _{1})}{(1+\alpha t _{2})}\Rightarrow \frac{1}{2}=\frac{(1+0.00125\times 27)}{(1+0.00125\times t)} $
$ \Rightarrow t=854{}^\circ C\Rightarrow T=1127K $
BETA
