Two light bulbs \(P\) and \(Q\) are identical in all respects, except that \(P's\) filament is thicker than \(Q's.\) If the same potential difference is applied to each, then …
(A) \(P\) will burn brighter because it has the greater resistance.
(B) \(Q\) will burn brighter because it has the greater resistance.
(C) \(P\) will burn brighter because it has the lower resistance.
(D) \(Q\) will burn brighter because it has the lower resistance.
Thabiseng connected four identical light bulbs in a circuit as shown to the right. She observes that the brightness of bulb \(A\) varies if some of the switches are closed. In which case will bulb \(A\) burn brightest?
(A) \(S_1\) closed with \(S_2\) and \(S_3\) open
(B) \(S_1\) and \(S_2\) closed with \(S_3\) open
(C) \(S_1,\)\(S_2\) and \(S_3\) closed
(D) \(S_1,\)\(S_2\) and \(S_3\) open
Two identical light bulbs \(X\) and \(Y,\) which are rated at \(60\; W;\)\(240\; V,\) are connected in series to a \(240\; V\) source as shown in the diagram below. If point \(A\) in the circuit is now connected to point \(B\) by a piece of copper wire with very low resistance, how will the brightness of each bulb change?
(A) Both \(X\) and \(Y\) will burn brighter.
(B) Both \(X\) and \(Y\) will burn less brightly.
(C) \(X\) will burn brighter and \(Y\) will not burn.
(D) \(Y\) will burn brighter and \(X\) will not burn.
A \(200\; V\) electrical outlet is protected by a circuit breaker. The circuit breaker will cut out if the current drawn from the outlets exceeds \(16\; A.\) A \(1000\; W\) toaster and a \(2000\; W\) kettle can be connected to the outlet, either singly, or both in parallel using a double adapter. Which use of the appliances will trip the circuit breaker?
(A) the toaster used on its own
(B) the kettle used on its own
(C) the toaster and the kettle together
(D) none of the above
Two resistors of resistance \(2R\) and \(3R\) are connected in series with a battery, which has an emf of \(E\) and an internal resistance \(R.\) What is the potential difference across the resistor of resistance \(2R\)?