In a meter bridge experiment, for measuring unknown resistance ‘S’, the null point is obtained at a distance 30 cm from the left side as shown at point D. If R is 5.6 kΩ, then the value of unknown resistance ‘S’ will be ___Ω.
Fig. Meter Bridge
In a meter bridge experiment, for measuring unknown resistance ‘S’, the null point is obtained at a distance 30 cm from the left side as shown at point D. If R is 5.6 kΩ, then the value of unknown resistance ‘S’ will be ___Ω.
Correct Answer: 2400
Approach Solution - 1
In a meter bridge setup, the balance condition for measuring resistance is given by the equation:
S/R = l/(100-l)
where S is the unknown resistance, R is the known resistance (5.6 kΩ), l is the length of the wire from one end to the null point (30 cm), and (100-l) is the remaining length (70 cm).
Now, let's calculate the unknown resistance S:
S = R × l/(100-l)
Substitute the values:
S = 5600 × 30/70
S = 2400 Ω
Upon calculating, the value of S is 2400 Ω, which fits within the given range of [2400, 2400]. Thus, the calculated unknown resistance is confirmed to be accurate.
Approach Solution -2
The correct answer is 2400
\(\frac{R}{S}=\frac{70}{30}\)
\(S=\frac{3}{7}×5.6×10^3\)
\(=2.4×10^3Ω=2400Ω\)
\(\therefore\) the value of unknown resistance ‘S’ will be 2400Ω.
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Concepts Used:
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Formula:
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