Question

Consider the following (a) Find the current through the resistor in the figure above. (Take R 8 2.) (b) If the resistor is made of carbon, what will its resistance be when its temperature is increased by 69.0 C°? (The temperature coefficient of resistivity for carbon is -5.0 x 10-4 (°c)-1.)

Answer 1

Solution :-

a)

using ohm's law,

V= IR

I =12/8 = 1.5Amps

b)

Resistance increase with increase in temperature as number of collisions increases

AR -αΔΤ α-temperature coefficient of resistance.

Or, expressed in terms of the resistance at some standard temperature from a reference table:

R-Ro

R(t) = 8(1 - 5*10^-4×69) = 7.724 ohm