Crucial definitions

Question 1

What is a scalar quantity

Answer 1

A quantity with size only.

• Temperature
• Mass
• Speed

Question 2

What is a vector quantity

Answer 2

A quantity with size and direction

• Gravity
• Force
• Acceleration

Question 3

What is DC current

Answer 3

Current that flows in one direction only

Question 4

What is AC current

Answer 4

Current that changes direction 50 times per second

Question 5

What does energy transferred =

Answer 5

Work done

Question 6

What is an unbalanced force?

Answer 6

Unbalanced force = mass * acceleration

Changes speed and changes direction

Question 7

What are he similarity’s of the electromagnetic spectrum?

Answer 7

• Travel at the same speed in a vacuum
• All transverse waves
• All electromagnetic waves

Question 8

What are the differences of electromagnetic waves?

Answer 8

• All have different frequency

- All have different wavelength

Question 9

Why would we use parallel circuits?

Answer 9

• Control each component separately

- If on component blows, the others still work

Question 10

How do you know whether the ray light goes towards or away from the normal in refraction?

Answer 10

• Less to more dense material it bend towards the normal

- More to less dense material it bend away from the normal

Question 11

What does an alternating magnetic field do?

Answer 11

• It produces a force

Question 12

What its important to remember about ultrasound waves?

Answer 12

• Rely on reflections

- You always have to half the distance cause it goes to a point then come back

Question 13

How to make ruler measurements more accurate?

Answer 13

-Make sure a ruler is at 90 degrees to avoid parallax.

Question 14

What should you always try and do when explaining an equation?

Answer 14

-Always try to use an equation

Question 15

Why does refractive index not have a unit?

Answer 15

-n=sin(i)/sin(r) tells me I am dividing two angles meaning the units cancel leaving NO units

Question 16

Define an Unbalanced force

Answer 16

-The total force acting on an object after you have added them as vectors

Question 17

What two things should you always talk about when talking about ionisation?

Answer 17

• Mass

- Charge

Question 18

Define a half-life?

Answer 18

-Time taken for half of the radioactive nuclei to decay

Question 19

What is precision?

Answer 19

• The scale (how precise)

Question 20

What is the accuracy?

Answer 20

• Other variables which affect the experiment

Question 21

What should you always talk about in a MOMENTUM question which asks ‘Explain why the cannon moves in the opposite direction.’

Answer 21

• Momentum = mass * velocity
• Momentum before firing is zero
• Momentum is conserved
• Firing canon must have an equal and opposite momentum to the cannonball

Question 22

How does a loudspeaker produce a sound wave?

Answer 22

• Current in the coil is alternating current
• The coil has a changing magnetic field
• The magnetic field of the magnet and magnetic field of coil interact
• Producing a force on the coil
• Vibrate loudspeaker cone

Question 23

What are two advantages of a circuit breaker?

Answer 23

• They can be reset unlike a fuse

- They cut off the circuit faster than a fuse

Question 24

In a nuclear power station, what does the energy start as?

Answer 24

• Nuclear

Question 25

When talking about a graph state whether…

Answer 25

it decreases or increases in a linear or non-linear way and how. Also, state directly proportional if through the origin. Also talk about correlation