Four resistances of 15 Ω, 12 Ω, 4 Ω and 10 Ω respectively in cyclic o...
Sure, I can explain the answer to this question.
A Wheatstone bridge is a circuit that is used to measure an unknown resistance. The circuit is balanced when the voltage drop across the two branches of the bridge is equal.
In this problem, the four resistances of the Wheatstone bridge are 15 Ω, 12 Ω, 4 Ω, and 10 Ω. The resistance that is to be connected in parallel with the resistance of 10 Ω is the resistance that will balance the bridge.
The resistance of the parallel combination of the 10 Ω resistor and the unknown resistor is given by
R_p = 10/(1 + R)
where R is the unknown resistance.
The bridge is balanced when the voltage drop across the two branches of the bridge is equal. This means that the current through the 10 Ω resistor is equal to the current through the parallel combination of the 10 Ω resistor and the unknown resistor.
Therefore, we have the following equation:
10/(1 + R) = 15/12
Solving for R, we get R = 10 Ω.
Therefore, the answer is option a.
Here is the detailed calculation:
The resistance of the parallel combination of the 10 Ω resistor and the unknown resistor is given by
R_p = 10/(1 + R)
The bridge is balanced when the voltage drop across the two branches of the bridge is equal. This means that the current through the 10 Ω resistor is equal to the current through the parallel combination of the 10 Ω resistor and the unknown resistor.
Therefore, we have the following equation:
10/R_p = 15/12
Substituting R_p = 10/(1 + R) into the equation, we get
10/(10/(1 + R)) = 15/12
Simplifying the equation, we get
1 + R = 12/5
Solving for R, we get R = 10 Ω.
As you can see, the answer is option a.