Figure 10 shows two electrical devices for heating water - Edexcel - GCSE Physics Combined Science - Question 6 - 2019 - Paper 1
Question 6
Figure 10 shows two electrical devices for heating water.
The current in the element of the immersion heater is 14 A.
The power of the immersion heater is 130 W.
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Worked Solution & Example Answer:Figure 10 shows two electrical devices for heating water - Edexcel - GCSE Physics Combined Science - Question 6 - 2019 - Paper 1
Step 1
Calculate the resistance of the immersion heater.
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Answer
To find the resistance of the immersion heater, we can use the formula for power:
P=I2R
Where:
P is the power (130 W)
I is the current (14 A)
R is the resistance
Rearranging the formula gives:
R=I2P
Substituting the values:
R=142130
Calculating:
R=196130≈0.6633≈0.66 (to 2 significant figures)
Step 2
State two differences between the movement of charge in the heating element of the kettle and the movement of charge in the immersion heater.
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Answer
The rate of flow of charge (current) in the immersion heater (14 coulombs per second) is greater than in the kettle (8.3 coulombs per second).
In the kettle's heating element, the direction of charge flow changes constantly due to the alternating current, while in the immersion heater, the flow of charge remains in the same direction (direct current).