Direct and Alternating Current
Physics ⇒ Electricity and Magnetism
Direct and Alternating Current starts at 9 and continues till grade 12.
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See sample questions for grade 9
A 12 V battery is connected to a 4 Ω resistor. What is the current through the resistor?
A current of 2 A flows through a resistor of 5 Ω. What is the voltage across the resistor?
A device requires 5 A of current at 12 V. What is the power consumed by the device?
A torch uses a 1.5 V cell. Is the current in the torch AC or DC?
Describe one advantage of using AC for long-distance power transmission.
Describe the shape of the graph of current versus time for AC.
Explain why AC is preferred over DC for transmission of electricity over long distances.
Explain why most electronic devices require DC to operate.
Explain why transformers cannot be used with DC.
If the frequency of an AC supply is 60 Hz, how many times does the current change direction in one second?
Name one device that uses direct current (DC) to operate.
What does the term 'alternating' mean in alternating current?
What is the main difference between AC and DC?
What is the main function of a rectifier in an electronic circuit?
What is the typical frequency of AC supplied in Europe?
Which type of current is typically supplied to homes and schools?
