Electricity and Electromagnetism Formulas

Question 1

Q = nq

Answer 1

total charge = number of charged particles x charge on the particle

Question 2

Charge on electron

Answer 2

• 1.6 x 10^-19 C

Question 3

Charge on proton

Answer 3

+ 1.6 x 10^-19 C

Question 4

E = V / d

Answer 4

electric field strength (N C^-1 or V m^-1) = voltage (V) / distance between plates (m)

Question 5

F = Eq

Answer 5

force on charged object (N) = electric field strength (N C^-1 or V m^-1) x size of charge (C)

Question 6

ΔEp = Eqd

Answer 6

electrostatic potential energy (J) = electric field strength (N C^-1 or V m^-1) x size of charge (C) x distance (m)

Question 7

Principle of Conservation of Energy

Answer 7

Ek = 1/2 mv^2 = ΔEp = Eqd

Question 8

I = Q / t

Answer 8

current (A) = charge (C) / time (s)

Question 9

V = ΔE / q

Answer 9

voltage (V) = change in potential energy (J) / charge (C)

Question 10

Ohm’s Law

Answer 10

voltage (V) = current (A) x resistance (Ω)

Question 11

Resistance in Series

Answer 11

R total = R1 + R2 + R3 + …

Question 12

Total Current

Answer 12

I total = V supply / R total

Question 13

Resistance in Parallel Circuits

Answer 13

1 / R total = 1 / R1 + 1 / R2 + 1 / R3 + …

Question 14

P = ΔE / t

Answer 14

power (W) = energy (J) / time (s)

Question 15

P = V I

Answer 15

power (W) = voltage (V) x current (A)

Question 16

Mass on an Electron

Answer 16

9.11 x 10^-31 kg

Question 17

F = BIL

Answer 17

force on the wire (N) = magnetic field strength (T) x current (A) x length of current-carrying wire that crosses magnetic field lines (m)

Question 18

F = Bqv

Answer 18

lorentz force on the particle (N) = magnetic field strength (T) x velocity (m s^-1) x charge (C)

Question 19

V = BvL

Answer 19

the induced voltage in wire crossing magnetic field lines (V) = magnetic field strength (T) x velocity of wire (m s^-1) x length of wire that crosses magnetic field lines (m)