Two identical steel balls mounted on wooden posts initially have different amount of charge as follows. The balls are allowed to touch and then are separated again. What’s the final charge on each ball in each case?
a) one +3 mC and the other +15 mC
b) one +12 mC and the other – 4 mC
One positive charge and one negative charge, each of magnitude 4×10-6C, are located a distance of 0.1 m from each other.
a) What’s the magnitude of force exerted on each charge?
b) On a drawing, indicate the direction of the forces acting on each charge.
c) Draw electric field lines between two charges.
A charge of 30 C passes at a steady rate through a resistor in a time of 5 s. What’s the current through the resistor?
Two identical light bulbs are connected to a battery with the electromotive force of 9 V. Each light bulb has the resistance of 10 W. 1) If the two light bulb connected in series,
a) draw the circuit and calculate the total resistance and current in the circuit;
b) calculate the voltage drop on each resistor.
2) If the two light bulb connected in parallel,
a) draw the circuit and calculate the total resistance and current in the circuit;
b) calculate current going through each resistor.
Why does the lighting system in your building have parallel circuits instead of series circuits?
Sample Solution
