Calculate the current in the 30 resistor in the diagram above if the battery is of negligible internal resistance
Attached Figure / Diagram
A
0.3A
B
0.4A
C
1.0A
D
1.5A
E
2.5A
Verified Correct Answer: C.
Physical Principles & Numerical Solution
Voltage across 0.8 \Omega = 2 V
→ Current through 0.8 \Omega (total current) = \(\frac{2}{0.8}\) = 2.5 A
The 3 \Omega and 2 \Omega are in parallel.
Current through 3 \Omega resistor = total current x (\(\frac{2}{(3 + 2)}\))
= 2.5 x (\(\frac{2}{5}\)) = 1.0 A
Source: Myschool Past Questions Archive (Record #25100)