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Multiple Choice Question Based on Passage
Stoke' s Law : A body falling through a viscous medium experiences a retarding force resulting in absorption of energy by the medium in the form of heat. The motion of the body produces a relative motion between the different layers of the fluid. Consequently, it experiences a force which tends to retard its motion. When a small spherical body is dropped in a viscous liquid such as glycerine, it accelerates first, but soon begins to experience a retarding force. When the retarding force becomes equal to the effective weight of the body in the fluid, the body experiences no net force and falls with a constant velocity known as the terminal velocity.
George Stokes found that a small spherical body of radius r moving with a uniform velocity v in a fluid of coefficient of viscosity

experiences a retarding force F given by

F = 6

Choose the correct statement. When a small body falls freely in a viscous fluid
(a) its speed increases indefinitely
(b) its speed first increases due to gravity and then decreases due to viscosity of the liquid, eventually the body comes to test in the liquid
(c) it accelerates first and then experiences deceleration until it aquires a constant velocity called terminal velocity
(d) the speed of the body remains constant throughout the motion

Chemistry

True or False :
The reactivity of an acid derivative in its reaction with a nucleophile decreases as the base strength of the leaving group increases.

Mathematics

Passage Based Question
Passage I
A class consists of n students. For 0

n, let E_k denote the event that exactly k student out of n pass in the examination. Let P(E_k) = p_k and let A denote the event that a student X selected at random pass in the examination.
If (E_k)