Question

6.
The resistance of bulb filament is 100 ohm at a temperature
of 100°C. If its temperature coefficient of resistance be
0.005°C. its resistance will become 200 ohm at a temperature
of
(a) 500°C
(b) 200°C
(c) 200°C
(d) 400°C​

Answer 1

Answer:

Answer is d, 400 c............

Answer 2

Answer:

Explanation:

R1 = R'[1+ π×100] = 100 ----- (a)

R2 = R'[1+π×T] = 200 ------ (b)

Where R1 is resistance @ 100°c , R2 is resistance @ T°c and π is Temp. coefficient per °c .

SO ON DIVIDING equation -- (a) and (b) and putting π = 0.005 We Get,

200/100 = 1 + πT/1 + 100π ,

2 = 1 + 0.005T/1 +100×0.005

*T= 400 °C ✓