The picture shows a battery connected to two wires in parallel. Both wires are m
ID: 2141268 • Letter: T
Question
The picture shows a battery connected to two wires in parallel. Both wires are made of the same material and are of the same length, but the diameter of wire A is twice the diameter of wire B.
(True/False) The resistance of wire B is twice as large as the resistance of wire A.
(True/False) The curent through the battery is five times larger than the current through wire B.
(True/False) The voltage drop across wire B is larger than the voltage drop across wire A.
(True/False) The power dissipated in wire A is 16 times the power dissipated in wire B.
(True/False) The resistance of wire B is four times as large as the resistance of wire A.
Explanation / Answer
Since Wire "A" has 2 times thediameter of Wire "B',
Wire "B" will have {(2)^2 = 4} times more resistance
than Wire "A".
(A) ----> TRUE
(B) ----> TRUE
(If Wire "B" carries 1 Amp, Wire "A" willcarry 4 amps,
for total of 5 Amps.)
(C) ----> FALSE
(Each wire dissipatesV2/R. Since voltage is same for both
wires, power dissipated varies with ratio ofresistances.
Hence, Wire "A" dissipates 4 times more power than Wire "B".
(D) ----> FALSE
(Voltage drop is equal across both wires.)
(E) ----> FALSE
(Wire "B" resistance is 4 times that ofWire "A".)