Electricity

Question 1

Coulomb

Answer 1

One coulomb is the charge moved when a current of 1 amp flow for 1 second of time.

Question 2

Kirchhoff’s 1st Law

Answer 2

(sum of/total) current into a junction equals the (sum of/total) current out.
Consequence of conservation of charge.

Question 3

Mean drift velocity

Answer 3

the average displacement/distance travelled of the electrons along the wire per second.
(they move slowly in one direction through the metal/Cu lattice )

Question 4

Potential difference

Answer 4

energy transfer per unit charge

from electrical to other forms.

Question 5

Volt

Answer 5

1 Volt is defined as the potential difference when 1 Joule of electrical potential energy is transferred to another form of energy per coulomb of charge moving through a component

Question 6

Electromotive force

Answer 6

The Emf of a device is defined as the electrical potential energy supplied per unit charge as it passes through the device.

Question 7

Resistance

Answer 7

Resistance = voltage / current.
Ratio of voltage to current.
Voltage per unit current.

Question 8

ohm

Answer 8

1 ohm is defined as the resistance of a component when a constant potential difference of 1 volt, applied across the component, produces through the component a current of 1 ampere

Question 9

ohms law

Answer 9

For a metallic conductor at constant temperature, the current in the conductor is directly proportional to the pd across its ends.

Question 10

Resistivity

Answer 10

The resistance across 2 faces of a material with unit cross sectional area and unit length.

Question 11

Power

Answer 11

Power is the amount of energy transferred per unit time.

Question 12

Kilowatt-hour (kWh)

Answer 12

(a unit of) energy equal to 3.6 MJ or 1 kW for 1 h.

The energy transferred when 1 kWh device is run for 1 hour.

Question 13

Kirchhoff’s 2nd Law

Answer 13

sum of) e.m.f.s = (sum /total of) p.d.s/sum of voltages in/around a (closed) loop (in a circuit) .
Energy is conserved