Four ammeter M1, M2, M3 and M4 with the following specifications

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Four ammeter M₁, M₂, M₃ and M₄ with the following specifications are available:
Instrument Type Full scale Accuracy value (A)% of FS
M₁ 3½ digit dual scope 20 ± 0.10
M₂ PMMC 10 ± .20
M₃ Electrodynamic 5 ± 0.50
M₄ Moving iron 1 ± 1.00
A current of 1 A is to be measured. To obtain minimum error in the reading, one should select meter

1. M₁
2. M₂
3. M₃
4. M₄

Correct Option: C

M₁ = 20 × 0.001 = 0.02,

∴ Relative error at 1A =	0.02	= 2%
	1

M₂ = 10 × 0.002 = 0.02,

∴ Relative error =	0.02	= 2%
	1

M₃ = 5 × 0.005 = 0.025,

∴ Relative error =	0.025	= 2.5%
	1

M₄ = 1 × 0.01 = 0.01,

∴ Relative error =	0.01	= 1%
	1