Formulas

Question 1

formula for calculating current

Answer 1

current = amount of charge / time (I = Q/t)

Question 2

formula for calculating charge

Answer 2

charge = current x time (Q = It)

Question 3

formula for calculating time ( with current and charge)

Answer 3

time = charge / current (t = Q/I)

Question 4

in the formula triangle consisting of current, charge and time, which one is at the top

Answer 4

charge (Q)

Question 5

formula for calculating energy (j)

Answer 5

energy (j) = charge x potential difference (E = QV)

Question 6

formula for calculating charge (with energy and pd)

Answer 6

charge = energy / potential difference (Q = E/V)

Question 7

formula for calculating potential difference

Answer 7

pd = energy / charge (V = E/Q)

Question 8

in the formula triangle consisting of energy, charge and potential difference, what is at the top

Answer 8

energy (E)

Question 9

what are watts in relation to joules and how would you calculate it

Answer 9

watts is the rate at which joules (energy) is used up, so 100J over 10s = 10W

Question 10

if you have 2 resistors in series, both with 5 ohms of resistance, hat would the total resistance around the circuit be

Answer 10

5 + 5 = 10 ohms, the resistance increases

Question 11

if you have 2 resistors in parallel with 5 ohms of resistance(one on one channel and the other on the parallel channel) what would the resistance be

Answer 11

1/5 + 1/5 = 2/5, the resistance becomes less

Question 12

formula for calculating resistance (with v and i)

Answer 12

resistance = potential difference / current (R = V/I)

Question 13

formula for calculating potential difference (with r and i)

Answer 13

potential difference = resistance x current (V = RI)

Question 14

formula for calculating current (with v and r)

Answer 14

current = potential difference / resistance (I = V/R)

Question 15

in the formula triangle consisting of current, resistance and potential difference what is at the top

Answer 15

potential difference (V)

Question 16

the three power equations

Answer 16

p = e/t (power  = energy /time)
p = iv (power = current x potential difference)
p = I^2 x R (power = current squared x resistance)

Question 17

formula for calculating energy (with three variables)

Answer 17

e = I x t x v (energy = current x time x potential difference)

Question 18

formula for power (with potential difference and current)

Answer 18

power = potential difference x current (P = VI)