The acceleration due to gravity (g) is given by: g = GM/R2, where; M is mass of the Earth remains constant, R, the radius of the Earth, shrinks by 1%, so R’= 0.99R. Science and Technology 585 New g’: g’= G M/(0.99R)2 = g/(0.99)2 (0.99)2 = (1 - 0.01)2 Using ((a – b)2 = a2 –b2 + 2.a.b) = 1 + (0.01)2- 2 × 1 × (0.01) = 1.0001- 0.02 = 0.9801 (0.99)2 ~1 - 2(0.01) = 0.98 So: g’= g. 1/(0.98) = g.(1.02) This means g increases by 2%. Directions (Q-224-230): The following two items consist of two statements, one labeled as the 'Assertion (A)' and the other as 'Reason (R)'. You have to answer these items using the code given below. 224. Assertion (A): With the increase of temperature, the viscosity of glycerine increases. Reason (R): Rise of temperature increases kinetic energy of molecules. Codes:

Question

The acceleration due to gravity (g) is given by: g = GM/R2, where; M is mass of the Earth remains constant, R, the radius of the Earth, shrinks by 1%, so R’= 0.99R. Science and Technology 585 New g’: g’= G M/(0.99R)2 = g/(0.99)2 (0.99)2 = (1 - 0.01)2 Using ((a – b)2 = a2 –b2 + 2.a.b) = 1 + (0.01)2- 2 × 1 × (0.01) = 1.0001- 0.02 = 0.9801 (0.99)2 ~1 - 2(0.01) = 0.98 So: g’= g. 1/(0.98) = g.(1.02) This means g increases by 2%. Directions (Q-224-230): The following two items consist of two statements, one labeled as the 'Assertion (A)' and the other as 'Reason (R)'. You have to answer these items using the code given below. 224. Assertion (A): With the increase of temperature, the viscosity of glycerine increases. ​ Reason (R): Rise of temperature increases kinetic energy of molecules. Codes:

YESPYQ · Accepted Answer

Correct answer: A is false but R is true. Viscosity is a measure of a fluid›s resistance to flow. It describes the internal friction of a moving fluid. Glycerine is a viscous liquid, meaning it has a relatively high resistance to flow at room temperature. Assertion (A) is false: The viscosity of liquids generally decreases with an increase in temperature. This is because higher temperatures lead to increased molecular motion, which weakens the intermolecular forces that cause viscosity. Reason (R) is true: Kinetic energy is the energy of motion. When the temperature of a substance increases, the molecules gain more kinetic energy, causing them to move faster. 225

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