Electricity

Question 1

Current in a wire consist of a flow of …

Answer 1

electrons from negative to positive

Question 2

Conventional current is drawn from …

Answer 2

Positive to negative

Question 3

Current is defined as

Answer 3

The rate of flow of charge

Question 4

Current in an electrolyte solution is a flow of

Answer 4

Ions

Question 5

Charge has a unit of the

Answer 5

Coulomb

Question 6

The coulomb is defined as

Answer 6

One coulomb of electric charge passes a point in one second when there is an electric current of one ampere

Question 7

What is the charge of an electron?

Answer 7

1.6*10^-19

Question 8

What is Kirchhoff’s first law?

Answer 8

At any point in an electrical circuit the sum of the currents into that point is equal to the sum of the currents out of the point, electrical charge is conserved

Question 9

Current in a series circuit is

Answer 9

The same at all points

Question 10

What is the definition of p.d.?

Answer 10

The energy transferred from electrical energy to other forms per unit charge

Question 11

What is electromotive force?

Answer 11

The energy transferred from chemical energy to electrical energy per unit charge

Question 12

What is the definition of the volt?

Answer 12

The pd across the component when one joule of energy is transferred per 1 coulomb passing through the component

Question 13

What is the definition of resistance?

Answer 13

The ratio of the pd across the component to the current in the component (R=v/I)

Question 14

What is the definition of the ohm?

Answer 14

The resistance of a component that has a pd of one volt per unit ampere

Question 15

What is resistance?

Answer 15

The ratio of the p.d. across the component to the current in the component

Question 16

In a series circuit the supply p.d. is …

Answer 16

equal to the sum of the p.d.s across the individual components in the circuit

Question 17

What is the definition of the ohm?

Answer 17

The ohm is the resistance of a component that has a p.d. of 1 volt per unit ampere

Question 18

In a parallel circuit the pd …

Answer 18

across every parallel branch is equal

Question 19

What is Ohm’s law?

Answer 19

The potential difference across a conductor is directly proportional to the current in the component as long as its temperature remains constant

Question 20

Equation linking resistivity, cross sectional area and length

Answer 20

P=r x a/l

Question 21

What are the three equations used to calculate power?

Answer 21

P=iv
P=i^2R
P=v^2/R

Question 22

What is the definition of power?

Answer 22

The rate at which energy is transferred

Question 23

The kilowatt hour is an alternative unit for…

Answer 23

Energy

Question 24

What the definition of the kilowatt hour?

Answer 24

The energy transferred by a 1kw device in a time of an hour

Question 25

1kwh=

Answer 25

3.6 MJ

Question 26

Kirchoffs 2nd law states:

Answer 26

The sum of the emfs round a loop in a circuit is equal to the sum of the pd in the same loop

Question 27

Internal resistance is defined as

Answer 27

The resistance of a source of emf due to its construction

Question 28

Terminal pd is defined as

Answer 28

The pd across a source

Question 29

Lost volts are

Answer 29

The pd across the internal resistance of a source of emf

Question 30

Equation linking lost volts, emf and terminal pd

Answer 30

Emf= lost volts + terminal pd

Question 31

What is the potential divider equation

Answer 31

Vout = vin x R2/R1+R2