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QUESTION 9 (Start on a new page.) The diagram below shows a simplified version of an AC generator - NSC Physical Sciences - Question 9 - 2017 - Paper 1
Question 9
QUESTION 9 (Start on a new page.) The diagram below shows a simplified version of an AC generator. The diagram illustrates the component arrangement with a coil ro... show full transcript
Worked Solution & Example Answer:QUESTION 9 (Start on a new page.) The diagram below shows a simplified version of an AC generator - NSC Physical Sciences - Question 9 - 2017 - Paper 1
Step 1
9.1 Name the component in this arrangement that makes it different from a DC generator.
Answer
The component that differentiates this AC generator from a DC generator is the slip rings. Unlike DC generators, which use a commutator, slip rings allow for the continuous flow of alternating current.
Step 2
9.2 Sketch a graph of induced emf versus time for TWO complete rotations of the coil.
Answer
The graph representing the induced emf versus time will be a sine wave that starts from 0. In one complete cycle, it rises to a maximum positive value, returns to 0, then descends to a maximum negative value before returning to 0 again. For two complete rotations, the graph should have two full cycles drawn between specific time intervals (t0 to t2).
Step 3
Step 4
9.4 Define the term root mean square (rms) value of an AC potential difference.
Answer
The root mean square (rms) value of an AC voltage is defined as the value of the AC voltage which would produce the same amount of energy transfer as a direct current (DC) voltage across a resistive load. It is mathematically given by:
oot{2}}$$Step 5
9.5 Calculate the rms current passing through the appliance.
Answer
To calculate the rms current ( I_{rms}) passing through the appliance, we can use the power equation:
Rearranging this gives:
I_{rms} = rac{P}{V_{rms}}
Substituting the given values:
I_{rms} = rac{1500 ext{ W}}{240 ext{ V}} = 6.25 ext{ A}
Thus, the rms current passing through the appliance is 6.25 A.