Science Test 1/5/25

Question 1

What is lens?

Answer 1

A piece of glass or other transparent material shaped to refract light towards or away from a focus.

Question 2

What is an image?

Answer 2

A representation of an object.

Question 3

What is focus?

Answer 3

(1) A poit where many rays of light from an object meet. (2) The process of refracting light rays so they meet.

Question 4

What is refraction?

Answer 4

When light changes direction when it enters a new medium.

Question 5

What is focal length?

Answer 5

The distance from the centre of a lens to where the lens focuses light from a distance object.

Question 6

What is the speed of light?

Answer 6

Light travels at a constant speed of 300000 km/s or 300000000 m/s in a vacuum.

Question 7

What are luminous objects?

Answer 7

An object that gives out light/emit.

Question 8

What’s an incident ray?

Answer 8

The ray of light that hits the surface of a mirror.

Question 9

What’s a reflected ray?

Answer 9

The ray that reflects the mirror.

Question 10

What’s a normal?

Answer 10

An imaginary line at 90° to the mirror.

Question 11

What’s an angle of incidence?

Answer 11

Angle between the incident ray and the normal.

Question 12

What is angle of reflection?

Answer 12

Angle between the normal and the reflected ray.

Question 13

What’s refraction?

Answer 13

When light passes from one substance into another more dense substance it changes direction.

Question 14

What’s the interface?

Answer 14

The boundary that’s between the substances where refraction occurs.

Question 15

What’s the retina?

Answer 15

A photosensitive layer of cells at the back of the eye.

Question 16

What is the cornea?

Answer 16

Transparent outer part of our eye.

Question 17

What’s the sclera?

Answer 17

Hard structure forming the outside of the eye.

Question 18

What’s the iris?

Answer 18

A muscle that controls how much light get in.

Question 19

What’s the optic nerve?

Answer 19

It sends electrical impulses from the eye to the brain.

Question 20

What does the pupil do?

Answer 20

Changes size to adjust the amount of light.

Question 21

What does the lens do?

Answer 21

Focuses light entering the eye.

Question 22

What is the name of the straight line that shows the direction light travels?

Answer 22

Ray.

Question 23

Name one source of light.

Answer 23

Various answers (just say sun bro).

Question 24

What happens when light hits a shiny surface?

Answer 24

It reflects.

Question 25

What do we call materials that do not let any light pass through them?

Answer 25

Opaque.

Question 26

What is the term for materials that let some light through but scatter it?

Answer 26

Translucent.

Question 27

What do we call the bouncing back of light from a surface?

Answer 27

Reflection.

Question 28

Draw and label a simple ray diagram to show how we see an object.

Answer 28

(In words): Light rays reflect off the object and travel in straight lines to your eyes. The arrows should go from the object to the eye.

Question 29

What is a shadow and how is it formed?

Answer 29

A shadow is a dark area where light is blocked by an opaque object.

Question 30

What is the difference between a luminous and a non-luminous object?

Answer 30

👉 Luminous objects give off their own light (e.g. the Sun); non-luminous objects only reflect light (e.g. the Moon).

Question 31

Give one example of a translucent material.

Answer 31

Frosted glass.

Question 32

Why can’t we see around corners?

Answer 32

👉 Because light travels in straight lines and doesn't bend around corners.

Question 33

Why do we see objects as colored?

Answer 33

👉 Because objects reflect some wavelengths (colors) of light and absorb the rest. The color we see is the one that is reflected.

Question 34

What happens to white light when it passes through a prism?

Answer 34

👉 It is split into the colors of the visible spectrum (a rainbow) – this is called dispersion.

Question 35

Name the colors of the visible spectrum in order.

Answer 35

👉 Red, Orange, Yellow, Green, Blue, Indigo, Violet.

Question 36

What is refraction?

Answer 36

👉 The bending of light when it passes from one material to another (like air to water).

Question 37

Why does a pencil look bent when placed in a glass of water?

Answer 37

👉 Because of refraction – the light rays change direction as they pass from water to air.

Question 38

What part of the eye detects light?

Answer 38

The retina.

Question 39

What is the function of the lens in the eye?

Answer 39

👉 To focus light onto the retina so we can see clearly.

Question 40

What do we call the process when light changes direction as it passes from air to glass?

Answer 40

Refraction

Question 41

What are light waves?

Answer 41

Transverse.

Question 42

Sound waves are_____________.

Answer 42

Longitudinal.

Question 43

Describe the difference between a series and a parallel circuit. (6 marks)

Answer 43

Series: - Current same throughout the circuit. - Voltage shared across components. - Only one path to go. Parallel: - Current splits between branches. - Voltage same throughout branches. - More than one path to go.

Question 44

Why is brass used in plug pins?

Answer 44

Good conductor, doesn't rust and is stronger than copper.

Question 45

Why is plastic used to wrap around wires?

Answer 45

It's a good insulator and malleable/bendy.

Question 46

Why is copper used in wires?

Answer 46

It's practical and can move around easier.

Question 47

What are the three pins in a UK plug and what does each one do? (6 marks)

Answer 47

Live wire: carries current from the power station. This brown wire has a votage of 230v. Neutral wire: Completes the circuit and is the return path to the power station. This blue wire should stay at 0v. Earth wire: Connects all the metal parts of an appliance to a large metal spike in the ground. This yellow and green wire should stay at 0v.

Question 48

Explain the three different ways we are protected from an electric shock when using household appliances. (6 marks)

Answer 48

Plastic is an insulator wrapped around wire to prevent direct contact with electricity. The earth wire has less resistance than us. If a fault occurs, current will flow through the earth wire to the ground. Fuses are thin wires which limit the amount of current, they melt, breaking the circuit and keeping us safe from electric shock.

Question 49

How is resistance caused?

Answer 49

When the electrons collide with the particles.

Question 50

What is resistnace measured in?

Answer 50

Ohms Ω.

Question 51

How does resistance in current work?

Answer 51

The more electrons bump into particles (ions), the slower they move, so current decreases. If a component has a high resistance, it slows the current down even more.