AS1 1.9 Electric Current, Charge, PD and EMF

Question 1

What is the equation for current?

Answer 1

I = Q/T
I = current
Q = charge
T = time

Question 2

What is another equation for charge carriers?

Answer 2

Q = ne
Q = charge (in Coulombs)
n = number of electrons
e = electron charge (ALWAYS 1.6 x 10^-19)

Question 3

What are the charge carriers in a circuit?

Answer 3

Electrons

Question 4

What is an equation for voltage?

Answer 4

V = W/Q
V = Voltage
W = Work Done
Q = Charge

Question 5

What is an equation for power

Answer 5

P = IV or I^2R
P = Power
I - current
V = Voltage
R = Resistance

Question 6

What is Electromotive Force (E.M.F) and the equation for it?

Answer 6

E.M.F of a battery is the amount of mechanical/chemical energy being transferred/changed to electrical energy per unit charge (V =W/Q)

Question 7

What is potential difference (P.D) and the equation for it?

Answer 7

P.D is the amount of electrical energy being converted to other types of energy.

Question 8

What is the difference between E.M.F and P.D?

Answer 8

E.M.F is the energy supplied, P.D is the energy consumed

Question 9

when is the E.M.F and P.D different and the same?

Answer 9

They are the same when there is no current or it is an open circuit and they are different when there is current flowing through it.

Question 10

What is terminal P.D?

Answer 10

The voltage across the terminals when a current is being drawn from the source