- #1
Sabeshan Ratneswaran
- 18
- 1
Homework Statement
The cell in the circuit has an emf of 2.0 V. When the variable resistor has a resistance of 4.0 Ω, the potential difference (pd) across the terminals of the cell is 1.0 V.
What is the pd across the terminals of the cell when the resistance of the variable resistor is 12 Ω?
A
0.25 V
B
0.75 V
C
1.33 V
D
1.50 V
Homework Equations
The only relevant equation I am thinking of is V=IR
The Attempt at a Solution
There are two ways I tried to solve this problem [/B]
1) by using proportion so if I volt = 4 ohms then what would 12 ohms would be... The answer came out to 3 which is wrong because it can not be more the emf voltage as it is voltage source.
2) It has to be more that 1 volt because we know that as the voltage increase the resistance also increase, so this means I can eliminate the multiple choice A and B. so now there are two choices, it can be either 1.50 V or or 1.33V.
Please help me on this question guys. Teach me the proper method to solved this question. Thanks indeed
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