The cross-sectional area of one limb of a U-tube manometer

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The cross-sectional area of one limb of a U-tube manometer (figure shown below) is made 500 times larger than the other, so that the pressure difference between the two limbs can be determined by measuring h on one limb of the manometer. The percentage error involved is

1. 1.0
2. 0.5
3. 0.2
4. 0.05

Correct Option: C

Fall in larger limb = Rise in smaller limb
A₁∆h = A₂h

or	∆h	=	A₂	=	1
	h		A₁		500

% error =	∆h	× 100 =	1	× 100 = 0.2%
	h		500