NEET 2022 · PhysicsWheatstone bridgePrevious Year Question
A Wheatstone bridge is used to determine an unknown resistance X by adjusting the variable resistance Y. For the most precise measurement of X, the resistances P and Q:
Answer: (B) Should be approximately equal and small. \textbf{Answer:} (2) approximately equal and small \textbf{Solution:} At balance X/Y = P/Q.
- A.Should be approximately equal to 2X
- B.Should be approximately equal and small✓
- C.Should be very large and unequal
- D.Do not play any significant role
Correct Answer
(B) Should be approximately equal and small
Solution & Explanation
\textbf{Answer:} (2) approximately equal and small \textbf{Solution:} At balance X/Y = P/Q. Sensitivity is greatest when the bridge is symmetric (P Q) and the arm resistances are small (large branch currents large galvanometer deflection per unit imbalance). Hence P and Q should be approximately equal and small.
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