An operating electric circuit consists of a lamp and a length of nichrome wire connected in series to a 12- volt battery. As the temperature of the nichrome is decreased, what happens to the equivalent resistance of the circuit and the power developed by the lamp?

Question

anonymous · Answer

In most metals resistance increases as temperature increases, which means if the temperature decreases then the resistance, also, decreases.

Power developed by the lamp can be calculated as : $$\ P=VI=V \frac{V}{R}= \frac{V^2}{R} $$ 
Where P- power, V- voltage, I-current, R-resistance
(I got that using ohms law)

From this you can deduce that if you decrease the temperature you also decrease the resistance thus increasing power developed by the lamp.

anonymous · Answer

thanks a bunch! this helped a lot

anonymous · Answer

No problem