GCSEPhysResPowerNrgUse13

Question 1

Equation for total Resistance of a series combination of resistors

Answer 1

R_total = R₁ + R₂ + R₃…

Question 2

electrical power equation

Answer 2

P = VI

Question 3

Electric energy equation

Answer 3

E = ItV

Question 4

Equation for total Resistance of a parallel combination of resistors

Answer 4

1/R_total = 1/R₁ + 1/R₂ + 1/R₃

Question 5

Alternative equation for total resistance of a parallel combination of 2 resistors only.

Answer 5

R_total = product/sum

Question 6

Equation for Ohm’s Law

Answer 6

V = IR

Question 7

Equation to find energy used in kilowatt-hours (kWh)

Answer 7

Energy in kWh = power in kW x time in hours

Question 8

As the current through a filament lamp increases the resistance of the filament …?

Answer 8

increases

Question 9

The unit of electrical resistance is the …?

Answer 9

Ohm (Ω)

Question 10

The yellow and green wire in a three-pin plug is the …?… wire

Answer 10

Earth

Question 11

A graph of I against V for a piece of metal wire at constant temperature is a …?????

Answer 11

straight line through the origin

Question 12

A graph of I against V for a light-bulb filament curves from …?… to shallow

Answer 12

steep

Question 13

The total resistance R of two identical resistors r connected in parallel is …?

Answer 13

r/2

Question 14

If the length of a piece of wire is increased its resistance…?

Answer 14

increases

Question 15

If the diameter of a piece of wire is increased its resistance…?

Answer 15

decreases

Question 16

The Earth wire and …?… together protect the user from electric shock and the equipment from damage.

Answer 16

fuse

Question 17

The fuse in a plug is always connected to the …?… wire.

Answer 17

live

Question 18

The colour of the live wire in a plug.

Answer 18

brown

Question 19

As seen through the cap of the plug, the Neutral wire is connected to the …?… hand pin.

Answer 19

left

Question 20

The unit of electrical power is the …?

Answer 20

Watt (W)