Q. 785.0( 1 Vote )

# Each question con

Answer :

Assertion is correct and Reason is correct explanation of the given assertion.

Explanation:

Assertion (A):

Given: A coin which is 1.75 cm in diameter and 2 mm thick.

A cuboid with dimensions (10cm × 5.5cm × 3.5cm)

A coin is in the form of a cylinder.

Volume of the Cylinder is given by: πr^{2}h

Let V_{1} be the volume of the coin.

∴ V_{1} = πr^{2}h

⇒ V_{1} = π × ()^{2} × (here, 1.75 is the diameter,∴ radius = , and 1mm = cm)

⇒ V_{1} = π × (0.875)^{2} × 0.2 = cm^{2}

Volume of a cuboid is given by: l × b × h

Let V_{2} be the volume of the of the cuboid.

∴ V_{2} = l × b × h

⇒ V_{2} = 10 × 5.5 × 3.5 = 192.5 cm^{2}

Let ‘n’ be the number of coin melted .

∴ n × V_{1} = V_{2}

⇒ n × = 192.5

⇒ n = 192.5 × = 400

∴ n = 400

That is 400 coin when melted can be moulded into a cuboid of given dimensions.

Reason(R):

Volume of a cylinder of base radius r and height h is given by V= (πr^{2}h) cubic units. And, area of a cuboid = (l × b × h) cubic units.

∴ Assertion is correct and Reason is correct explanation of the given assertion.

Rate this question :