First question :The unit of measurement of the electric charge is :
1)kg m^2sec^-2 volt^-1 2)volt sec^-1ohm^-1 3)watt volt^-1sec^-1
Second question:
A ball with 200 gm of mass falls of an altitude of 2 meters towards the ground , because of the non elastic chock with the ground , the ball lost 25% of its energy. Find the maximum reached altitude of the ball when it rebounds up .
Third question:
Two lamps with resistance of 1 ohm and 4 ohm are connected in series with a battery of 10 volts.Find the needed resistance to be connected in order that the consumed potency becomes one third the consumed potency before adding the resistance.

1. Use your formulae:

where Q is charge, I is current, and t is time and;

where V is voltage, I is current and R is resistance.

2. Find the potential of the ball, through , where E is potential energy, m is the mass of the ball, g the acceleration due to gravity and h the altitude.

Then, find 25% of that energy.

Finally, through again, find h, with the new value of Ep you just found.

3. Find the total resistance in series, through

If you want to reduce the amount of voltage consumed, you'll have to decrease the resistance. This is done by connecting a resistor in parallel. I assume you know your formula to find the total resistance of resistors in parallel. You then equate the total resistance to 1/3 of what you've got initially to find the resistance you need to introduce.

Hope it helped! :) Post back if you want more details, but try on your own first, k? :)