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Which of the following is not a true statement about the entropy of a system? (A) Entropy is a measure of the randomness in a system (B) The entropy of an amorphous solid is greater than that of a crystalline solid (C) The entropy of a spontaneous reaction cannot decrease (D) The entropy of an isolated system will spontaneously increase or remain constant

The entropy of a spontaneous reaction cannot decrease Entropy is a measure of randomness in a system. Hence, entropy of a spontaneous reaction... View Article

At 80 degree C the vapour pressure of pure liquid A is 520 mm of Hg and that of pure liquid B is 1000 mm Hg. If a mixture solution of A and B boils at 80 degree and 1 atm pressure, the amount of A (mole percent) in the mixture is (1 atm = 760 mm Hg) (A) 50% (B) 54% (C) 32% (D) 44%

Given Let mole fraction of A in solution be xA and mole fraction of B in solution be XB Then, at 1 atm pressure On substituting, we get,... View Article

Name the stage of cell cycle at which one of the following events occur: (A) Chromosomes are moved to spindle equator. (B) Centromere splits and chromatids separate. (C) Pairing between homologous chromosomes takes place. (D) Crossing over between homologous chromosomes takes place.

(A) Chromosomes are moved to the spindle equator in the Metaphase. (B) Centrosomes split and chromatids separate in the Anaphase (C) Pairing... View Article

The extra embryonic membrane that involve in the formation of the placenta in human is (A) Chorion (B) Allantois (C) Yolk sac (D) Amnion

Chorion The placenta is defined as an organ that develops during pregnancy in mammals. The placenta provides oxygen and nutrients to the growing... View Article

From a given sample of uniform wire, two circular loops p and q are made, P of radius r and Q of radius nr. If the M.I of Q about its axis is 4 times than that of P, then value of n is: (A) (4)^1/3 (B) (4) ^2/3 (C) (4)^1/4 (D) (4)^1/2

Given that two circular loops P and Q are made, P of radius r and Q of radius nr. Let the mass of ring P = M Hence, mass of ring Q = nM (Since... View Article

Write a square matrix of order 2, which is both symmetric and skew symmetric

For a symmetric matrix = AT ..... (1) For a skew symmetric matrix = -AT ...... (2) Adding on (1) and (2), we get, 2A = 0 A = 0 Hence, required... View Article

What is rib cage?

Ribs are the long curved bones which constitute the rib cage. They articulate posteriorly with the vertebral column and terminates anteriorly as... View Article

04 Oct 2021: UPSC Exam Comprehensive News Analysis

Oct 4th, 2021, CNA:- Download PDF Here TABLE OF CONTENTS A. GS 1 Related HISTORY 1. Chola inscriptions on civic officials’ eligibility B. GS 2... View Article

03 Oct 2021: PIB Summary & Analysis

Context: Electricity (Transmission System Planning, Development and Recovery of Inter-State Transmission Charges) Rules 2021 promulgated by... View Article

0.4i+0.8j+ck represents a unit vector when c is

1) -0.2 2) √0.2 3) √0.8 4) 0 Answer: 2) √0.2 Solution: = 0.16 + 0.64 +c2 = 1 =... View Article

A particle of mass 2 mg moves with constant speed and is found to pass two points 5.0 m apart in a time interval of 5 ms. Find the kinetic energy of the particle

1) 1 J 2) 2 J 3) 3 J 4) 4 J Answer: 1) 1 J Solution: Velocity = Distance/Time = 5/5 x 10-3 m/s = 1000 m/s Kinetic energy = (1/2)mv2... View Article

A spring of force constant 800 Nm^-1 has an extension of 5cm. The work done in extending it from 5 cm to 15 cm is

1) 16 J 2) 8 J 3) 32 J 4) 24 J Answer: 2) 8 J Solution: Force constant, k = 800 N/m Work done in extending from 5 cm to 15 cm... View Article

A bullet of mass 10 g is fired horizontally with a velocity 1000 ms^-1 from a rifle situated at a height 50 m above the ground. If the bullet reaches the ground with a velocity 500 ms^-1, the work done against air resistance in the trajectory of the bullet is (take g = 10 m^-2)

1) 5005 J 2) 3755 J 3) 3750 J 4) 17.5 J Answer: 2) 3755 J Solution: Work done against the air resistance is the energy lost W = (mgh... View Article

A particle of mass 100 g is thrown vertically upwards with a speed of 5 m/s. The work done by the force of gravity during the time, the particle goes up is

1) –0.5 J 2) –1.25 J 3) 1.25 J 4) 0.5 J Answer: 2) –1.25 J Solution: Mass = 100 g Speed, u = 5 m/s Work done by... View Article

A body moves a distance of 10 m along a straight line under action of 5 N force. If work done is 25 J, then the angle between the force and direction of motion of the body will be

1) 75° 2) 60° 3) 45° 4) 30° Answer: 2) 60° Solution: Distance, S = 10 m Force, F = 5 N Work done, W = 25 J W =... View Article

When a force is applied to a moving body, its motion is retarded. Then, the work done is

1) positive 2) negative 3) zero 4) positive and negative Answer: 2) negative Solution: Work is said to be done on that body when a... View Article

Force of 50 N acting on a body at an angle θ with horizontal. If 150 J work is done by displacing it 3 m, then θ is

1) 60° 2) 30° 3) 0° 4) 45° Answer: 3) 0° Solution: The horizontal component of force = Fcos θ Work done =... View Article

A spring stores 1 J of energy for compression of 1 mm. The additional work to be done to compress it further by 1 mm is

1) 1 J 2) 2 J 3) 3 J 4) 4 J 5) 0.5 J Answer: 3) 3 J Solution: W1 = (1/2)kx2 = (1/2)k(1 x 10-3)2 k = 2 x 106 W2 = (1/2)(2 x... View Article

A ball is dropped from a height of 20 m. If the coefficient of restitution is 0.9, what will be the height attained after the first bounce?

1) 1.62 m 2) 16.2 m 3) 18 m 4) 14 m Answer: 2) 16.2 m Solution: Ball is dropped from a height, h= 20 m coefficient of restitution =... View Article

For inelastic collision between two spherical rigid bodies

1) the total kinetic energy is conserved 2) the total mechanical energy is not conserved 3) the linear momentum is not conserved 4) the linear... View Article