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In the Maxwell bridge as shown in the figure below, the values of resistance Rx and Inductance Lx of a coil are to be calculated after balancing the bridge. The component values are shown in the figure at balance. The values of Rx and Lx will respectively be:
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- 375 ohm, 75 mH
- 75 ohm, 150 mH
- 37·5 ohm, 75 mH
- 75 ohm, 75 mH
- 375 ohm, 75 mH
Correct Option: A
Applying the balance condition relation
Here,
Z1 = Rx + JωLx
Z2 = 200Ω
Z3 = 750Ω
| Z4 = R4 || | |
| JωC4 |
or
| Z4 = 4000 || | |
| Jω (0·05 × 10–6) |
This arrangement is shown below:
| = | ||
| Z2 | Z4 |
or
Z1Z4 = Z2Z3
or
| (Rx + JωLx) |  |  | = R2R3 | |
| R4 + (1/JωC4) |
On comparing, we get
| Rx = | = | = 375Ω | ||
| R4 | 4000 |
Lx = R2R3C4 = 2000 × 750 × 0·05 × 10–6 = 75mH.
