Phy 202 & 214 Quiz 20
Resistors Feb 29,
2008
1.
What is the resistance of a carbon resistor at
20 ¡ if it is a cylinder of radius 4 mm and a length of 2 m ? (Resistivity of carbon is 3.5 x 105
V m, and it's Temperature
coefficient of
resistivity is -0.5 x 10-3)
2.
At 20¡ C, the carbon resistor in an electric
circuit connected to a 5 V battery has a resistance of 200 ohms. What is the current in the
circuit when
the temperature is - 20¡.
(Resistivity of carbon is 3.5 x 105 ohm- m, and it's Temperature
coefficient of
resistivity is - 0.5 x 10-3)