Download CURRENT, VOLTAGE, RESISTANCE

CURRENT, VOLTAGE, RESISTANCE
1. How long does it take for a charge of 3.50 C to pass through the
cross-sectional area of a wire that is carrying a current of 0.570A?
2. A small toy car draws a 0.50-mA current from a 3.0-V nickel-cadmium
battery. In 10.0 minutes of operation,
a) how much charge flows through the toy car?
b) how much energy is lost by the battery?
3. A car’s starter motor draws 50.0 A from the car’s battery during
startup. If the startup time is 1.50 s, how many electrons pass a given
location in the circuit during that time?
4. Explain the difference between “drift velocity” and the speed with
which electrical energy travels through a circuit.
5. If you double the voltage across a resistor while at the same time
cutting its resistance to one-third its original value, what happens to
the current in the resistor?
6. Two ohmic resistors are connected to the electrodes of a 12.0-V
battery one at a time. The current in resistor A is twice that in
resistor B. What can you say about their resistance values?
7. Filaments in light bulbs usually fail just after the bulbs are turned
on, rather than when they have already been on for a while. Why?
8. A Van de Graaff generator is charged so that the electric field at its
surface is 3.00 x 104 N/C.
a) What is the electric force on a proton released at the surface of the
generator?
b) What is the proton’s acceleration at this moment?
9. An ion is displaced through a potential difference of 60.0 V and
experiences an increase of electrical potential energy of 1.92 x 10-17 J.
Calculate the charge on the ion.
10. A force of 4.30 x 10-2 N is needed to move a charge of 56.0 microC
a distance of 20.0 cm in the direction of a uniform electric field.
What is the potential difference that will provide this force?