Two identical moving coil galvanometers have 10Ω resistance and full scale deflection at 2µA current. One of them is converted into a voltmeter of 100mV full scale reading and the other into an ammeter of 1mA full scale current using appropriate resistors. These are then used to measure the voltage and current in the Ohm's law experiment with R = 1000Ω resistor by using an ideal cell. Which of the following statement(s) is/are correct?

Correct option is D. The measured value of R will be 978Ω < R < 982Ω
v = 100 × 10⁻³ V [Ref. image 1]
v = Ig(Rg + Rv) 10⁻¹; 2 × 10⁻⁶ = Rg + Rv 5 × 10⁴ Ω ≈ Rv (Rv < 10⁵ Ω [Ref. image 2]
IgRg = (I − Ig)S
S = 2 × 10⁻⁶; × 10¹⁰⁻³ − 2 × 10⁻⁶ [Ref. image 3]
S = 2 × 10⁻⁵ × 10³ ⇒ 2 × 10⁻²; ⇒ 20mΩ
RA = 20 × 10⁻³ × 10¹⁰ = 20 × 10⁻³ Ω
i = ε(1000 × 50 × 10³)/51 × 10³ = 51ε/5 × 10⁴ (≈ RA → 0)
r = i(Rv/51 × 10³) = ε/1000
measured resistance ∴ Rm = I × 1000
I = ε/51ε × 5 × 10⁴ = 5 × 10⁴/51 = 980.4 Ω.