A circuit is wired with a power supply, a resistor and an ammeter (for measuring current). The ammeter reads a current of 30 mA (milliAmps). Determine the new current if the voltage of the power supply was .. increased by a factor of 2 and the resistance was held constant

a. I sub new = 48 mA (Current is directly proportional to voltage; a doubling of the voltage will double the current.)
b. I sub new = 72 mA (Current is directly proportional to voltage; a tripling of the voltage will triple the current.)
c. I sub new = 12 mA (Current is directly proportional to voltage; a halving of the voltage will halve the current.)
d. I sub new = 12 mA (Current is inversely proportional to resistance; a doubling of the resistance will halve the current.)
e. I sub new = 6 mA (Current is inversely proportional to resistance; a quadrupling of the resistance will reduce the current to one-fourth its original value.)
f. I sub new = 48 mA (Current is inversely proportional to resistance; a halving of the resistance will double the current.)
g. I sub new = 24 mA (Current is directly proportional to voltage; a doubling of the voltage will double the current. But current is also inversely proportional to the resistance; a doubling of the resistance will halve the current. These two factors offset each other and there is no overall change in the current.)
h. I sub new = 144 mA (Current is directly proportional to voltage; a tripling of the voltage will triple the current. But current is also inversely proportional to the resistance; a halving of the resistance will double the current. So the new current can be found by tripling and then doubling the old current of 24 mA.)
i. I sub new = 6 mA (Current is directly proportional to voltage; a halving of the voltage will halve the current. But current is also inversely proportional to the resistance; a doubling of the resistance will halve the current. So the new current can be found by halving and then halving again the old current of 24 mA.)