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 11
A 12 V battery supplies a current of 3 A to a circuit. How much electrical power is being delivered?
A DC circuit has a resistance of 5 Ω and a current of 2 A. What is the voltage across the resistor?
A generator produces an AC voltage described by V(t) = 100 sin(314t). What is the frequency of the AC voltage?
A lamp rated at 60 W, 120 V is connected to a 120 V DC supply. What current does it draw?
A resistor of 10 Ω is connected to an AC source with an RMS voltage of 100 V. What is the RMS current through the resistor?
Describe the function of a commutator in a DC generator.
Explain why AC is preferred over DC for long-distance power transmission.
Explain why electronic devices often require DC even when supplied with AC from the mains.
If the peak voltage of an AC supply is 325 V, what is its RMS voltage?
In a certain country, the AC mains supply is 240 V, 50 Hz. What does 50 Hz represent?
State one advantage of using AC over DC for household power supply.
State one key difference between direct current (DC) and alternating current (AC).
What is the root mean square (RMS) value of an AC current with a peak value of 10 A?
