Physics · Magnetism and Electromagnetic Induction
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What shunt resistance must be connected across a Galvanometer of 20 Ω resistance which gives full scale deflection with 2.0 A current, so as to convert it into an Ammeter of range 10 A?
- A
5 Ω
- B
2 Ω
- C
3 Ω
- D
4 Ω
Explanation:
Galvanometer resistance = G = 20Ω
Current = I1 = 10A
Current = I2 = 2 A
Shunt resistance = Rs = ?
So,
n = I1 / I2
n = 10 / 2
= 5
Applying the formula:
Rs = G / n - 1
= 20 / 5 - 1
= 20 / 4
Rs = 5 ohms
This is the correct answer. The shunt resistance is calculated using the formula Rs = G / (n - 1), where n = I1 / I2. Substituting the given values, we find that Rs = 5 Ω.
This is incorrect. Using a shunt resistance of 2 Ω would not provide the desired ammeter range of 10 A. Double-check your calculations using the correct formula.
This is incorrect. A shunt resistance of 3 Ω is too low to achieve the required range conversion. Ensure you are using the correct formula and values.
This is incorrect. Using a shunt resistance of 4 Ω would not convert the galvanometer to the desired range of 10 A. Verify your calculations.
Tagged under Physics · Magnetism and Electromagnetic Induction · 2009