DC and AC Circuits

Question 1

Formula for resistance in terms of resistivity

Answer 1

R = pL/A

Question 2

Power dissipated by a resistor

Answer 2

P = IV

Question 3

Power dissipated in transmission

Answer 3

P = I^2 * R

Question 4

How to calculate capacitance (charge and voltage)

Answer 4

C = Q/V

Question 5

Capacitance (geometry)

Answer 5

C = E0 (A/d) (E0 = permittivity of free space)

Question 6

Electric field between parallel plates

Answer 6

E = V/d

Question 7

Energy stored in capacitor

Answer 7

U = 1/2 CV^2

Question 8

Capacitance with dielectric

Answer 8

C’ = KC

Question 9

Irms of AC current

Answer 9

Irms = Imax/ √2

Question 10

What happens when you insert a dielectric in a capacitor when a battery is connected? (in terms of C, Q, V, U)

Answer 10

C goes up, charge goes up, voltage stays same, energy stored goes up

Question 11

What happens when you insert a dielectric in a capacitor when a battery is disconnected? (in terms of C, Q, V, U)

Answer 11

C goes up, charge stays same, voltage goes down, energy stored goes down

Question 12

Actual voltage supplied to circuit by battery

Answer 12

V = E.cell - I R.internal