P 2

Question 1

What is thermal conduction ?

Answer 1

The process where energy is transferred by vibrating particles in a substance .

Question 2

Is the direction of energy transfer always from hot to cold ?

Answer 2

Yes

Question 3

What are three examples of substances with high thermal conductivity

Answer 3

. Diamond
. Aluminium
. Graphite

Question 4

What is an insulator ?

Answer 4

A substance that is a poor thermal conductor.

Question 5

What are insulators used for ?

Answer 5

Insulators are used to reduce energy transfers .

Question 6

What three things does the energy transfer through a layer of insulating material depend on ?

Answer 6

. The temprature difference across the material
. The thickness of the material
. The thermal conductivity

Question 7

What is specific heat capacity ?

Answer 7

The specific heat capacity of a substance is the energy needed to raise the temprature of 1kg of the substance by 1 degree

Question 8

What is the equation for specific heat capacity ?

Answer 8

Energy transferred / mass x change in temprature

Question 9

What is the independent variable in the specific heat capacity experiment ?

Answer 9

The time

Question 10

What is the dependent variable in the specific heat capacity experiment ?

Answer 10

Temprature

Question 11

What were the control variables in the specific heat capacity experiment ?

Answer 11

Material of the block , current supplied anc potential difference supplied .

Question 12

What is the aim of the specific heat capacity experiment ?

Answer 12

To determine the specific heat capacity of a substance , by linking the amount of energy transferred to the substance with the rise in temprature of the substance .

Question 13

What is the equipment used in the experiment ?

Answer 13

1kg block of metal
Thermometer
Immersion heater
Power supply
Stopwatch
Voltmeter
Ammeter

Question 14

What is the method of the specific heat capacity experiment ?

Answer 14

1. Start by assembling the apparatus, placing the heater into the top of the block
2. Measure the initial temprature of the aluminium block from the thermometer
3. Turn on the power supply and start the stopwatch
4. Whilst the power supply is on , the heater will heat up the block . Take several periodic measurements eg. Every one minute of the voltage and current from the voltmeter and ammeter respectivley , calculating an average for each at the end of the experiment up to 10 minutes .
5. Switch off the power supply , stop the stopwatch and leave the apparatus for about a minute . The temprature will still rise before it cools .
6. Monitor the thermometer and record the final temprature reached for the block

Question 15

How can the rate of energy transfer from houses be reduced ?

Answer 15

Loft insulation
Cavity wall insulation
Double glazed windows
Aluminium foil behind radiators