Current Electricity Charging Discharging Of Capacitors Question 364

Question: Resistance of tungsten wire at $ 150{}^\circ C $ is $ 133,\Omega $ . Its resistance temperature coefficient is $ 0.0045/{}^\circ C $ . The resistance of this wire at $ 500{}^\circ C $ will be

[DPMT 2004]

Options:

A) $ 180,\Omega $

B) $ 225,\Omega $

C) $ 258,\Omega $

D) $ 317,\Omega $

Show Answer

Answer:

Correct Answer: C

Solution:

$ \frac{R _{150}}{R _{500}}=\frac{[1+\alpha (150)]}{[1+\alpha (500)]} $ . Putting $ R _{150}=133\Omega $ and $ \alpha =0.0045/{}^\circ C, $ we get $ R _{500}=258\Omega $