Final answer:
The total resistance (Req) in the series circuit is 24 Ohms, and the current (I) flowing through each bulb is 0.5A; thus, option (a) I=0.5A is correct, and the other given options are incorrect.
Step-by-step explanation:
Calculating Total Resistance and Current in a Series Circuit
When three bulbs, each with a resistance of 8 Ohms, are connected in series, the total resistance (Req) of the circuit is the sum of the individual resistances. This is found by the formula Req = R1 + R2 + R3. Therefore, Req equals to 24 Ohms (since 8 Ohm + 8 Ohm + 8 Ohm = 24 Ohm). To find the current (I) flowing through each bulb, Ohm's Law (I = V/R) is applied. With a voltage source (V) of 12 volts, the current would be I = 12 V / 24 Ohm, resulting in 0.5A.
Accordingly, the correct answers to the student's question are:
Req = 24 Ohms, which is not among the given options.
I = 0.5A, which corresponds to option (a).
Neither option (b) nor the incorrect values for Req (options c and d) apply in this case.