Answer:
Potential difference is the work done in moving a positive test charge from infinity to the point in question.
Voltage is an expression of PD. (Joules / Coulomb)
Say that a capacitor has a PD of 5 Volts. The work in moving a positive test charge from the positive plate to the negative plate is -5 Joules/Coulomb or -5 volt. (At the positive plate the positive test charge (1 Coulomb) already has a PD of + 5 Volts.)
If you decrease the pressure of a fixed amount of gas, its volume will increase.
R=U/I so
U=RxI
U= 10 x 42
U= 420 volts
Answer:
9.2 amperes
Explanation:
Ohm's law states that the voltage V across a conductor of resistance R is given by 
Here, voltage V is proportional to the current I.
For voltage, unit is volts (V)
For current, unit is amperes (A)
For resistance, unit is Ohms (Ω)
Put R = 12.5 and V = 115 in V=RI
