In the circuit shown, R 1 = 10 ?, R 2 = 100 ?, and R 3 = 1000 ?. The wires in th
ID: 1357075 • Letter: I
Question
In the circuit shown, R1 = 10 ?, R2 = 100 ?, and R3 = 1000 ?. The wires in the circuit are ideal (have no resistance) but the battery has a small internal resistance. Which of the following statements about R3 is (are) true? Select all answers that are correct.
a. I3 is zero because the current goes through the path of least resistance.
b. I3 is zero. The voltage across R3, ?V3, is zero because all the potential is used up in the internal resistance of the battery, R1, and R2.
c. ?V3 is greater than ?V1 and ?V2 because R3 has the largest resistance.
d. ?V3 is smaller than ?V1 and ?V2 because R3 has the largest resistance.
e. I3 will decrease if R1 is removed from the circuit.
f. I3 will increase if R2 is removed from the circuit.
g. None of the above.
Explanation / Answer
The current passing through R3 is least as compared to other resistors as its resistance is higher, but current through R3 is not zero
Thus ( a) and ( b) are not correct
The voltage drop across all of the resistors in a parallel resistive network is the same. Thus, the options ( c) and (d) are not correct.
As R1 removed, the resultant resisance of the circuit would increases and hence current through R3 decreases
Thus, the correct option is ( e).