Physics · Current Electricity
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Two copper conductors have equal lengths. The cross-sectional area of one conductor is four times that of the other. If the conductor having a smaller cross-sectional area has a resistance of 40 ohms, the resistance of the other conductor will be
- A
160 Ohms
- B
80 Ohms
- C
20 Ohms
- D
10 Ohms
The resistance of the conductor is given by:
R = ρ/A
As the area of cross section increases, resistance decreases.
Resistance of thin wire = 40 Ω
Resistance of thick wire = 40/4 = 10 Ω
A is incorrect as it is numerical it can have only one answer.
B is incorrect as the correct answer is 10.
C is incorrect as the correct answer is 10.
The resistance of the conductor is given by:
R=p/A
As the area of the cross section increases, resistance decreases.
Resistance of thin wire = 40 Q
Resistance of thick wire= 40/4 = 10 Ω
Tagged under Physics · Current Electricity · 2021