Question

The resistance of a nichrome wire at 20 oC is 10 Ω . If its temperature

coefficient of resistivity of nichrome is 0.004 /oC, find the resistance of the

wire at boiling point of water. Comment on the result.​

Answer 1

Answer:

Resistance of a nichrome wire at 0°C, R0

= 10 Ω Temperature co-efficient of resistance,

α = 0.004/°C

Resistance at boiling point of water, RT = ?

Temperature of boiling point of water, T = 100 °C

RT =R0 ( 1 + αT) = 10[1 + (0.004 x 100)]

RT = 10(1 +0.4)

= 10 x 1.4 R = 14 Ω

As the temperature increases the resistance of the wire also increases.

Answer 2

Answer:

SOL:

Ro - 10 Ω

T- 100°C

To-20°C

α- 0.004/°C

Rt-?

we will find Rt..?

then,

Rt = Ro ( 1+ α ( T-To) )

= 10 ( 1+0.004 × ( 100°-20°)

= 10( 1+0.004× ( 80° )

= 10 (1+0.320)

= 10 ( 1.320)

=13.2Ω