P2

Question 1

What materials are the best conductors of electricity?

Answer 1

Metals

Question 2

What materials are the best insulators and why?

Answer 2

Non-metals such as wood and Fibreglass as they don’t conduct the heat

Question 3

What happens to the rate of energy transfer through a material when the thermal conductivity of that material increases?

Answer 3

It increases

Question 4

What happens to the rate of energy transfer through a material when the layer of insulating material is thicker?

Answer 4

It is lower

Question 5

What type of radiation do all objects emit and absorb?

Answer 5

Infrared

Question 6

What happens to the amounts of infrared radiation an object emits in a given time when the temperature increases?

Answer 6

It emits more infrared radiation

Question 7

What is black body radiation?

Answer 7

Radiation emitted by a body that absorbs all the radiation incident on it

Question 8

Why does the temperature of an object increase?

Answer 8

Because it absorbs more radiation that it emits

Question 9

What are 2 factors that affect the earth’s temperature?

Answer 9

Absorption of infrared radiation from the sun and the emission of radiation from the earths surface and atmosphere

Question 10

What is specific heat capacity?

Answer 10

The quantity of thermal energy required to raise 1kg of a given material by 1 degree Celsius

Question 11

Instead of using scales, what might u use to maximise accuracy and efficiency?

Answer 11

A balance

Question 12

How do you find the mass, change in temperature and change in energy in the specific heat capacity equation?

Answer 12

Mass= balance
Change in temp= thermometer
Change in energy= joulemeter

Question 13

Instead of using a joule metre, how else could you find change in energy?

Answer 13

Use 2 equations:
Energy= Power X Time
To find time use a stopwatch and to find power do Power= current X potential difference
To find current use an ammeter and to find potential difference use a voltmeter

Question 14

How do you set up the specific heat capacity practical?

Answer 14

1 wire from the power pack to an ammeter, and from the ammeter to the thermometer. In the wire from the ammeter to the thermometer put a wire to a voltmeter, place another wire from the voltmeter to a immersion heater and from that wire back to the power pack, place a drop of water in both holes of a calorimeter and place on a heat proof mat, finally our safety goggles on.

Question 15

How long do you wait before you take measurements in the specific heat capacity test?

Answer 15

300seconds/ 5 minuites

Question 16

Name 2 insulation features in a house

Answer 16

Double glazed windows and draft excluders on doors to outside

Question 17

What is cavity wall insulation?

Answer 17

Insulation material that is used to fill the cavity between 2 brick layers of an external house wall

Question 18

Why does double glazed window reduce heat loss?

Answer 18

As the hot air has to conduct through 1 layer of glass, then radiate through a layer of argon which is difficult as argon is a rly poor heat conductor then conduct through a final layer of glass