8463/1H June 2020

Coach Name: Sir Muhammad Abdullah Shah

4. Figure 6​​ shows how much electricity was generated using coal-fired and gas-fired power stations in January for 5 years in the UK.

Figure 6

i-​​ Determine the percentage increase in electricity generated using gas-fired power stations from 2014 to 2018.​​ 

[2 marks]

ANSWER

Percentage increase=IncreaseOriginal Value×100

Percentage increase=10000-32003200×100

Percentage increase=212.5%

ii-​​ Give two environmental advantages of using a gas-fired power station to generate electricity compared with using a coal-fired power station.​​ 

[2 marks]

ANSWER

  • Sulfur dioxide isn’t emitted, so there is no chance of acid rain.​​ 

  • No solid waste

  • Contributes to glomal warming lesser than the coal-fired power station.​​ 

  • Coal mining is less hazardous than coal mining.

(You may choose any two points from above.)

The mean surface temperature of the sea changes throughout the year.​​ 

A change in the mean surface temperature from year to year indicates climate change.

Figure 7​​ shows how the mean surface temperature changed between 1988 and 2016.

iii-​​ A student does not believe that climate change is occurring.​​ 

Explain how the data in​​ Figure 7​​ suggests the student is wrong.​​ 

[2 marks]

ANSWER

The mean surface temperature is increasing.​​ In fact, over the a long period of time, the mean surface temperature has increased from 16.45 - 16.96.​​ 

iv- A thermistor can be used to measure temperature.​​ 

Figure 8​​ shows how the resistance of four different thermistors A, B, C and D, varies with temperature.

Which of the four thermistors would be the most suitable to measure​​ the surface temperature of the sea?

Tick () one box.

Explain your answer.

[3 marks]

ANSWER

Option C is correct as the chjange in resistance of this thermistor is greatest amongst all the thermistors.​​ 

Option A & B thermistors’ graph show that they have shown less​​ or​​ small change in their resistance. Whereas, the option D thermistor’s graph is has no data available between 0 to 40​​ whereas mean surface temperature lies in the range of​​ ​​ 16.45 - 16.96.