Question

If the full-scale deflection current of a multimeter is \(50\,\mu A\), its sensitivity is

• A. \(10\,k\Omega/V\)
• B. \(100\,k\Omega/V\)
• C. \(50\,k\Omega/V\)
• D. \(20\,k\Omega/V\)

Hint:

Lower current sensitivity ⇒ higher instrument sensitivity.

Answer 1

The Correct Option is D

Concept: Sensitivity of a voltmeter: \[ S = \frac{1}{I_g} \] (where \(I_g\) is full scale deflection current)

Step 1: Given current \[ I_g = 50\,\mu A = 50 \times 10^{-6} A \]

Step 2: Substitute in formula \[ S = \frac{1}{50 \times 10^{-6}} \]

Step 3: Calculate \[ S = \frac{1}{50} \times 10^6 = 0.02 \times 10^6 \]

Step 4: Simplify \[ S = 2 \times 10^4 \Omega/V \]

Step 5: Final Answer \[ \boxed{20\,k\Omega/V} \]