JEE 2020: Weekly Quiz 12 (21.07.2019) for JEE & BITSAT Exams

Question 1

If a circular iron sheet of radius 30 cm is heated such that its area increases at the uniform rate of 6πcm²/hr, then the rate (in mm/hr) at which the radius of the circular sheet increases is

Question 2

Which of the following statement is correct?

Question 3

Let f (x) = tan^–1 {φ (x)}, where φ (x) is monotonically increasing for 0 < x < π/2. Then f (x) is -

Question 4

Function f(x), g(x) are defined on [–1, 3] and f′′(x) > 0, g′′(x) > 0 for all x ∈ [–1, 3], then which of the following is always true?

Question 5

The greatest value of the function f(x) = tan^–1x –

log x in

is -

Question 6

The cubic polynomial function passing through (1, 2) with origin as the point of inflection is-

Question 7

Question 8

If

, then f(x) =

Question 9

Question 10

Question 11

A particle is projected with a velocity v sothat its horizontal range twice the greatest height attained. The horizontal range is

Question 12

A ball is dropped from height h on the ground. If the coefficient of restitution is e, the height to which the ball goes up after it rebounds for the nth time is

Question 13

What will be the force acting on a particle moving along a circle of radius R, if its kinetic energy k depends on the distance covered as k = as²?

Question 14

The circular motion of a particle with constant speed is

Question 15

A body of mass ‘m’ is travelling with a velocity ‘u’. When a constant retarding force ‘F’ is applied, it comes to rest after travelling a distance ‘s₁’. If the initial velocity is ‘2u’, with the same force ‘F’, the distance travelled before it comes to rest is ‘s₂’. Then

Question 16

An insect crawls up a hemispherical surface very slowly. The coefficient of friction between the insect and the surface is

. If the line joining the centre of the hemispherical surface to the insect makes an angle α with the vertical, the maximum possible value of α so that the insect does not slip is given by

Question 17

A flexible chain of weight W hangs between two fixed points A & B which are at the same horizontal level. The inclination of the chain with the horizontal at both the points of support is θ. What is the tension of the chain at the midpoint?

Question 18

A weight can be hung in any of the following four ways by string of same type. In which case is the string most likely to break?

Question 19

Two blocks are in contact on a frictionless table. One has mass m and the other 2m. A force F is applied on 2m as shown in the figure. Now the same force F is applied from the right on m. In the two cases respectively, the ratio force of contact between the two blocks will be:

Question 20

Water in a bucket is whirled in a vertical circle with a string attached to it. The water does not fall down even when the bucket is inverted at the top of its path. We conclude that:

Question 21

For the water gas reaction
C(s) + H₂O(g)

CO(g) + H₂(g)
At 1000 K the standard Gibbs free energy change of the reaction is –8.314 kJ/mol. Therefore at 1000 K the equilibrium constant of the above water gas reaction is-

Question 22

Which among the following reactions will be favoured at low pressure ?

Question 23

Which of the following is correct?

Question 24

For this reaction (ring closure), ΔH = – 49 kJ/mol, ΔS = –40.2 Jk^–1 mol^–1.
lower limit of temperature above which the forward reaction is spontaneous?

Question 25

k_sp for AgCl is-
Given: T = 25 °C

are 17.7, 13.2 and 23.0 cal/mol. (Antilog 0.21 =1.6)

Question 26

The total number of octahedral void(s) per atom present in a cubic close packed structure is:

Question 27

A metal crystallises in a face centered cubic structure. If the edge length of its unit cell is ‘a’, the closest approach between two atoms in metallic crystal will be:

Question 28

Which of one of the following pairs of molecules will have permanent dipole moments for both members?

Question 29

Which one of the following compounds has the smallest bond angle in its molecule?

Question 30

The “spin-only” magnetic moment [in units of Bohr magneton, (μ_B)] of Ni²⁺ in aqueous solution would be (At. No.. Ni = 28)