A 0–25A ammeter has a guaranteed accuracy of 1 per cent

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A 0–25A ammeter has a guaranteed accuracy of 1 per cent of full scale reading. The current measured by this instrument is 5A. The limiting error in percentage will be:

1. 1%
2. 5%
3. 10%
4. 25%

Correct Option: B

Given ammeter range 0 – 25A
relative error = E_r = 1% = 0·01
The magnitude of limiting error of the instrument
δA = E_r × A where, A is the true value
= 0·01 × 25
= 0·25A
The magnitude of the current being measured is 5.
The relative error at this current is

E_r =	δA	=	0.25	= 0.05
	A		5

or
percentage relative or limiting error = 5%.