- #1
physics604
- 92
- 2
1. A series circuit initially consists of a cell of unknown voltage, a resistor R2 of 4.0 Ω, and another resistor R2 of 6.0 Ω. A student measures the current through R2 to be 3.0 A. When a wrench that has a small resistance is dropped on the circuit, the current through R2 is reduced to 1.0 A. What is the current flowing through the wrench? (Assume the supply voltage remains constant.)
a) 1.0 A
b) 2.0 A
c) 5.0 A
d) 7.5 A
To summarize:
R1=4.0 Ω
R2= 6.0Ω
I2 initially= 3.0 A
I2 with wrench= 1.0 A
Find I (current) going through the wrench.
V=IR
My answer is a) 1.0 A, but it is wrong. The correct answer is c) 5.0 A but I don't understand why.
I was told that in a series circuit, the current should be the same throughout. So in the circuit (with wrench), if the current is measured after a resistor to have a current of 1.0 A, shouldn't the current through the wrench be the same?
a) 1.0 A
b) 2.0 A
c) 5.0 A
d) 7.5 A
To summarize:
R1=4.0 Ω
R2= 6.0Ω
I2 initially= 3.0 A
I2 with wrench= 1.0 A
Find I (current) going through the wrench.
Homework Equations
V=IR
The Attempt at a Solution
My answer is a) 1.0 A, but it is wrong. The correct answer is c) 5.0 A but I don't understand why.
I was told that in a series circuit, the current should be the same throughout. So in the circuit (with wrench), if the current is measured after a resistor to have a current of 1.0 A, shouldn't the current through the wrench be the same?