Static Electricity

Question 1

What happens when certain insulating materials are rubbed together?

Answer 1

Electrons are transferred from one material to the other. The one that gains electrons becomes negatively charged, and the one that loses electrons becomes positively charged.

Question 2

What type of charge do electrons carry?

Answer 2

Negative charge.

Question 3

What happens if two objects have the same type of charge?

Answer 3

They repel each other.

Question 4

What happens if two objects have opposite charges?

Answer 4

They attract each other.

Question 5

What type of force is exerted between charged objects without touching?

Answer 5

A non-contact force.

Question 6

Give an example of static electricity in everyday life.

Answer 6

When you rub a balloon on your hair and it sticks to a wall due to electrostatic attraction.

Question 7

What is sparking in static electricity?

Answer 7

A sudden discharge of electricity when the potential difference becomes high enough to overcome air resistance.

Question 8

What is potential difference in terms of static electricity?

Answer 8

The difference in electric potential between a charged object and the Earth.

Question 9

How does potential difference relate to sparking?

Answer 9

A higher charge increases the potential difference; if it becomes large enough, a spark may jump to a nearby earthed conductor.

Question 10

What is an electric field?

Answer 10

A region around a charged object where other charges experience a force.

Question 11

What happens to the strength of an electric field as you move further away from a charged object?

Answer 11

The electric field gets weaker.

Question 12

What does the direction of electric field lines show?

Answer 12

The direction a positive charge would move in the field.

Question 13

What is the shape of the electric field around an isolated spherical charge?

Answer 13

Radial lines pointing outward from a positive charge or inward to a negative charge.

Question 14

How does the electric field explain non-contact forces?

Answer 14

A second charged object in the field experiences a force — attraction or repulsion — depending on the charges.

Question 15

How can electric fields explain sparking?

Answer 15

When the field is strong enough, it can ionise air particles, allowing a current to flow as a spark.

Question 16

What is the equation for density?

Answer 16

Density (ρ) = mass (m) ÷ volume (V)

Question 17

What is the unit of density?

Answer 17

Kilograms per cubic metre (kg/m³)

Question 18

Why do solids usually have a higher density than liquids or gases?

Answer 18

Because their particles are packed closely together.

Question 19

Describe the arrangement of particles in a solid.

Answer 19

Closely packed in a regular arrangement, vibrating in fixed positions.

Question 20

Describe the arrangement of particles in a liquid.

Answer 20

Close together but irregular and can move past each other.

Question 21

Describe the arrangement of particles in a gas.

Answer 21

Far apart and moving randomly at high speed.

Question 22

What happens to the mass of a substance when it changes state?

Answer 22

The mass is conserved.

Question 23

What type of change is a change of state?

Answer 23

A physical change, not a chemical one.

Question 24

How can you find the volume of an irregular object?

Answer 24

By using a displacement method with a measuring cylinder or eureka can.

Question 25

What is internal energy?

Answer 25

The total energy stored by particles in a system — both kinetic and potential energy.

Question 26

What happens to the internal energy of a substance when it is heated?

Answer 26

It increases, either raising the temperature or causing a change of state.

Question 27

State the equation linking energy, mass, specific heat capacity, and temperature change.

Answer 27

ΔE = m × c × Δθ

Question 28

Define specific heat capacity.

Answer 28

The energy required to raise the temperature of 1 kg of a substance by 1°C.

Question 29

What is specific latent heat?

Answer 29

The energy required to change the state of 1 kg of a substance without changing its temperature.

Question 30

State the equation for energy during a change of state.

Answer 30

E = m × L

Question 31

What is the specific latent heat of fusion?

Answer 31

The energy needed to change a substance from solid to liquid.

Question 32

What is the specific latent heat of vaporisation?

Answer 32

The energy needed to change a substance from liquid to gas.

Question 33

What happens to temperature during a change of state?

Answer 33

It stays constant, even though energy is still being added or removed.

Question 34

What happens to gas particles when temperature increases?

Answer 34

Their average kinetic energy increases, increasing pressure if volume is constant.

Question 35

What is the relationship between pressure and temperature in a gas at constant volume?

Answer 35

As temperature increases, pressure increases due to more frequent and forceful collisions.

Question 36

What is the relationship between pressure and volume of a gas (at constant temperature)?

Answer 36

They are inversely proportional: p × V = constant.

Question 37

How can doing work on a gas increase its temperature?

Answer 37

Work transfers energy to the gas particles, increasing their kinetic energy and internal energy.

Question 38

Give an example of doing work on a gas increasing temperature.

Answer 38

Compressing air in a bicycle pump causes the gas to heat up.