Physics

Question 0

What is the difference between series and parallel circuits?

Answer 0

A series circuit connects everything in one loop from one side of the battery or cell to the other.
A parallel circuit connects each component separately in its own loop

Question 1

What do all electric circuits have?

Answer 1

A cell, battery or power supply to provide an electrical current

Question 2

What do you use to measure electric current and what are the units you use?

Answer 2

Ammeter

Measured in amps (A)

Question 3

How would the readings on an ammeter change in a series and parallel circuit made up of two bulbs and one cell?

Answer 3

In the series circuit, the readings would remain the same around the whole circuit showing that the current isn’t used up by the components
In a parallel circuit the readings on the ammeters on each branch would add up to equal the reading of the main circuit. This shows that the current is split exactly in half between the two branches.

Question 4

What affects the electric current in a series circuit?

Answer 4

1) Number of cells

2) number and nature of components

Question 5

How do you measure voltage?

Answer 5

Use a voltmeter connected across a component, cell or power supply.

Question 6

How will the voltage be split between two identical bulbs in a circuit with one cell.

Answer 6

The voltage of the cell will be split in half between the two bulbs

Question 7

What is a magnetic field?

Answer 7

A region of space around a magnet that exerts an attractive force on certain materials that are magnetic

Question 8

When will two magnets repel or attract each other?

Answer 8

Repel- when two like poles are brought near each other, for example north and north, south and South
Attract- when two unlike poles are brought near each other, for example north and south

Question 9

What’s the difference between a magnet and a magnetic material?

Answer 9

A magnetic material will never repel, it will attract to either pole of a magnet whereas a magnet will repel one side and attract the other.

Question 10

What is an electromagnet?

Answer 10

A coil of wire connected to a cell or battery.

It can be switched on or off

Question 11

How do you change the strength of an electromagnet?

Answer 11

Change the number of coils
Change the size of the current (more or less cells)
Place a soft iron core in the coil to increase the strength.

Question 12

What is a force?

Answer 12

A push or pull

Question 13

What is a balanced force?

Answer 13

When forces of the same size are acting on an object in opposite directions

Question 14

How do balanced forces affect movement?

Answer 14

1) a stationary object will remain stationary if the forces are balanced or there are no forces
2) A moving object will continue at the same speed

Question 15

How do unbalanced forces affect movement?

Answer 15

The object will either speed up or slow down (acceleration or deceleration)

Question 16

What are the three forces that affect the movement of objects?

Answer 16

Weight
Friction- Resists movement of objects and tries to slow them down. Acts in the opposite direction of movement
Air resistance- resists the movement of objects through air. Can be reduced if object is streamlined

Question 17

What is the equation for speed?

Answer 17

Speed = distance➗time

Question 18

What is pressure?

Answer 18

Pressure is exerted when a force is applied over an area. The smaller the area that force is applied to, the greater amount of pressure is exerted.
Measured in newtons per mm/cm/m
Pressure = force ➗ area

Question 19

How do we see non-luminous objects?

Answer 19

Light from luminous objects reflects off them and into your eyes

Question 20

When measuring reflection what is:
A) Normal
B) Angle of incidence
C) Angle of reflection

Answer 20

A) a line drawn 90 degrees to the mirror
B) angle between normal and ray of light that hits mirror
C) angle between reflected ray of light and normal. It should be equal to the angle of incidence.

Question 21

What is diffuse reflection?

Answer 21

When light strikes an irregular surface meaning no clear image is seen as the light is reflected from all directions due to the uneven surface.

Question 22

What is refraction.

Answer 22

When light passes from one transparent material (medium) to another transparent material it changes direction.
It only works if the two materials are different.

Question 23

What is dispersion of light?

Answer 23

White light passes through a glass prism and splits into a spectrum of colours. The colours go in the order of the rainbow and red light is bent least whilst violet light is bent most.

Question 24

What do coloured filters do?

Answer 24

Filters white light

They only allow some colours of the spectrum through and absorb the others

Question 25

Explain how coloured objects reflect light and explain the two exceptions

Answer 25

The colour of an object is the colour of the light it reflects. All the other colours are absorbed.
Exceptions:
White- reflects all colours and absorbs none
Black- Reflects no colours and absorbs all.

Question 26

How do we hear sound?

Answer 26

Sound is produced through vibrations of objects.
Sound vibrations are funnelled down the ear canal from the outer ear and to the ear drum which vibrates. The vibrations are taken to the inner ear and eventually processed into electrical signals and sent to the brain.

Question 27

How is loudness measured?

Answer 27

In decibels (dB)

Question 28

What is pitch?

Answer 28

Pitch is how high or low a sound is.

It depends on the frequency of vibrations, the higher the frequency, the higher the pitch.

Question 29

How do you change loudness?

Answer 29

Measurement of how loud or soft a sound is
Depends on the amplitude of the vibrations causing the sound, amplitude is the biggest movement of the vibrating from its rest position.
The greater the amplitude, the louder the sound

Question 30

Compare light and sound

Answer 30

Light travels at a higher speed than sound.

Light can travel through a vacuum (empty space) but sound can’t because it needs a material to carry vibrations.

Question 31

What is an orbit?

Answer 31

The path a planet takes around the sun or a moon around a planet
It is usually an ellipse shaped path.
This is due to the very large gravitational pull from the sun

Question 32

What is the earth’s axis?

Answer 32

The earth spins around on a tilted axis and completes one rotation once every 24 hours. This gives us daytime and night-time because for 12 hours we face the sun and for the other 12 hours we don’t.
It gives the illusion of the sun and stars moving across the sky.

Question 33

How does the suns apparent movement change between summer and winter?

Answer 33

In summer the sun is high in the sky because we are tilted towards the sun. Daytime is longer than night-time. It is warmer
In winter we are tilted away from the sun making the sun appear lower in the sky. Playtime is shorter than night-time and it is colder

Question 34

What is a satellite?

Answer 34

A small object orbiting a larger object.
The earth is a natural satellite of the sun and the moon is a natural satellite of the earth
There are also artificial satellites that orbit earth.

Question 35

What are the three tasks that artificial satellites perform?

Answer 35

1) Monitoring the weather- Including the movement of the clouds so weather forecasts can be made. They orbit earth several times a day and pass over the north and south poles.
2) Communication- they link different places for TV, radio and phone calls. They orbit the equator and take 24 hours to complete the rotation
3) Exploration of the solar system- Orbit above the atmosphere. Have telescopes and observe the solar system and other things in space.

Question 36

What are the eight most common forms of energy?

Answer 36

Light, sound, electrical, kinetic, elastic potential, chemical, heat or thermal, gravitational potential

Question 37

What are non-renewable energy resources?

Answer 37

Resources that will run out one day
Cannot be replaced within a lifetime
Form over millions of years by heating and pressurising the remains of living things.
E.G. Oil, gas, coal

Question 38

What are renewable energy sources?

Answer 38

They won’t run out
Continually being replaced
E.G. Biomass, wind, waves, solar

Question 39

How can you store energy?

Answer 39

Energy can be stored to be used at another time.

E.G. A battery, compressed spring

Question 40

How does heat flow?

Answer 40

From hot to cold

Question 41

What is the difference between temperature and heat energy?

Answer 41

The bigger the object, the more heat energy it contains but it could be a lot colder than something smaller.

Question 42

What are the four methods of heat transfer?

Answer 42

Conduction- transfer through a substance from hot to cold without movement of the substance itself
Convection- transfer through particles from a hotter to a colder region
Radiation- Travels through a vacuum by waves
Evaporation- transfer due to loss of particles from the surface of fluids

Question 43

What is input, output and wasted energy?

Answer 43

Input energy is what is put in to something to make it work
Output energy is part of the input energy that is used where it is wanted
Wasted energy is the remainder of the input energy which is transferred in a non-useful way usually through heat or sound