Electricity N4 Definitions

Question 1

What is electric charge?

Answer 1

Electric charge is a property of particles, like electrons and protons, that causes them to experience a force in an electric field.

Question 2

What is the charge of an electron?

Answer 2

The charge of an electron is negative.

Question 3

What happens when like charges come near each other?

Answer 3

Like charges repel each other.

Question 4

What happens when opposite charges come near each other?

Answer 4

Opposite charges attract each other.

Question 5

What is electric current?

Answer 5

Electric current is the flow of electric charge through a conductor, typically measured in amperes (A).

Question 6

What is the unit of current?

Answer 6

The unit of current is the ampere (A).

Question 7

What instrument is used to measure current?

Answer 7

Current is measured using an ammeter.

Question 8

What is the formula relating charge, current, and time?

Answer 8

Q=I×tQ = I \times tQ=I×t, where QQQ is charge in coulombs (C), III is current in amperes (A), and ttt is time in seconds (s).

Question 9

What is voltage (or potential difference)?

Answer 9

Voltage is the energy transferred per unit charge as a charge moves between two points in an electric circuit. It is measured in volts (V).

Question 10

What is the unit of voltage?

Answer 10

The unit of voltage is the volt (V).

Question 11

What instrument is used to measure voltage?

Answer 11

Voltage is measured using a voltmeter.

Question 12

What is the relationship between energy, charge, and voltage?

Answer 12

V=EQV = \frac{E}{Q}V=QE​, where VVV is voltage in volts, EEE is energy in joules (J), and QQQ is charge in coulombs (C).

Question 13

What is resistance?

Answer 13

Resistance is the opposition to the flow of electric current in a material, measured in ohms (Ω).

Question 14

What is the unit of resistance?

Answer 14

The unit of resistance is the ohm (Ω).

Question 15

What is Ohm’s Law?

Answer 15

Ohm’s Law states that V=I×RV = I \times RV=I×R, where VVV is voltage in volts, III is current in amperes, and RRR is resistance.

Question 16

What factors affect the resistance of a wire?

Answer 16

Resistance is affected by the material, length, thickness, and temperature of the wire.

Question 17

In a series circuit, how is the current distributed?

Answer 17

In a series circuit, the current is the same at all points in the circuit.

Question 18

In a series circuit, how is voltage distributed?

Answer 18

In a series circuit, the total voltage is the sum of the voltages across each component.

Question 19

In a parallel circuit, how is the current distributed?

Answer 19

In a parallel circuit, the current splits between branches and may be different in each branch.

Question 20

In a parallel circuit, how is voltage distributed?

Answer 20

In a parallel circuit, the voltage across each branch is the same.

Question 21

What is electrical power?

Answer 21

Electrical power is the rate at which electrical energy is transferred by a circuit, measured in watts (W).

Question 22

What is the formula for electrical power?

Answer 22

P=V×IP = V \times IP=V×I, where PPP is power in watts, VVV is voltage in volts, and III is current in amperes.

Question 23

What is the relationship between power, energy, and time?

Answer 23

E=P×tE = P \times tE=P×t, where EEE is energy in joules (J), PPP is power in watts (W), and ttt is time in seconds (s).

Question 24

What is efficiency, and how is it calculated?

Answer 24

Efficiency is a measure of how much input energy is converted to useful output energy. Efficiency=UsefulEnergyOutputTotalEnergyInput×100%\text{Efficiency} = \frac{\text{Useful Energy Output}}{\text{Total Energy Input}} \times 100\%Efficiency=TotalEnergyInputUsefulEnergyOutput​×100%.