Phy 202 & 214 Quiz 21
Resistors March
3, 2008
1.
What is the resistance of a carbon resistor at
20 ¡ if it is a cylinder of radius 6 mm and a length of 3 m ? (Resistivity of carbon is 3 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 - 30¡.
(Resistivity of carbon is 3
x 105 ohm- m, and it's
Temperature coefficient of resistivity is - 0.5 x 10-3)
3.
When a parallel plate capacitor whose plates have area 2 m2
are connected to a 20 V battery the charge on the plates is 6
mC.
How far apart are the plates?