COMEDK Mock Test - 9 - JEE MCQ

Self potential energy of the sphere having mass m and radius r,

Hence, energy released in formation of the sphere is

Consider the equilibrium of wooden block.
Forces acting in the downward direction are

(a) Weight of wooden cylinder

(b) Force due to pressure (P₁) created by liquid of height h₁ above the wooden block is
= P₁ × π (2r)² = [P₀ + h₁rg] × π (2r)²
Force acting on the upward direction due to pressure P₂ exerted from below the wooden block and atmospheric pressure is

At the verge of rising

• Strong electromagnets are situated above the rails in some electrically powered trains.
• When the electromagnets are activated, the eddy currents induced in the rails oppose the motion of the train.
• When a changing magnetic flux is applied to a bulk piece of conducting material then circulating currents called eddy currents are induced in the material.
• So, by the above explanation, we can understand that the generation of eddy current depends on the magnetic field but it is independent of the direction of the magnetic field.
• Therefore, the eddy current will also generate when the north and the south poles are replaced with each other and that eddy currents induced in the rails oppose the motion of the train. So, the velocity of the train will decrease.

For deflection of θ/2, current also reduces to I/2 with shunt resistance S.
Hence,

Length of the antenna = 25 m
 = λ / 4
⇒ λ = 100m

According to first law of thermodynamics, for the path iaf,

Q_iaf = ΔU_iaf + W_iaf

or, ΔU_iaf = Q_iaf - W_iaf

= 50 - 20 = 30 cal

For the path ibf,

Q_ibf = ΔU_iaf + W_ibf

Since ΔU_iaf = ΔU_ibf, change in internal energy is path independent.

Q_ibf = ΔU_iaf + W_iaf

∴ W_ibf = Q_ibf - ΔU_iaf = 36 - 30 = 6 cal

Electronegativity:
 In a chemical bond, electron attraction capability of atoms is called electronegativity. 

EN of non-metal is higher than metal.

EN of elements increases as we go from left to right in the periodic table.

 ₃Li−1s²2s¹ donates one electron easily

In 1s²2s²2p⁶3s²3p⁶3d³, the number of unpaired electrons are 3.
In 1s²2s²2p⁶3s²3p⁶3d⁵, the number of unpaired electrons are 5.
In 1s²2s²2p⁶3s²3p⁶3d⁷, the number of unpaired electrons are 3.
In 1s²2s²2p⁶3s²3p⁶3d⁹, the number of unpaired electrons is 1.

The magnetic moment  where n is the number of unpaired electrons.

So, the more the number of unpaired electrons, the more is the magnetic moment. Hence, 1s²2s²2p⁶3s²3p⁶3d⁵ has the maximum magnetic moment.

Base BOH is dissociated as follows.

So, dissociation constant of BOH base,

At equilibrium, [B⁺] = [OH]^-

In general, higher the oxidation state, more is the covalent character of the oxide. Therefore, the only covalent oxide of iodine is I₂O₅, whereas I₂O₇ and I₂O₉ do not exist and I₂O₄ is iodyl iodate, i.e. [IO]⁺[IO₃]^-, which is ionic in nature.

A mixture of Conc. H₂SO₄ and K₂Cr₂O₇ called as chromic acid.

Chromic acid features chromium in an oxidation state of +6 . It is a strong and corrosive oxidizing agent.

It is capable of oxidising many forms of organic compounds, and many variants have been created for this reagent. Chromic acid is referred to as the Jones reagent in aqueous sulphuric acid and acetone, which oxidises primary and secondary alcohols into carboxylic acids and ketones, respectively, though rarely affecting unsaturated bonds.

The compounds are as follows.

They do not show optical isomerism because all possible spatial arrangements, for any of these complexes, will be exactly equivalent.
But, [Cr(C₂O₄)³]^3- is a chiral molecule and is optically active.
The two enatiomers of tris(oxalato)chromate(III) ion are shown below.

According to Faraday' first law of electrolysis:

The euivalent weight of Ag is maximum among these hence, AgNO₃ solution will deposit the maximum mass of the metal at the cathode on electrolysis.

Since, Toulene is ortho/para-directing. therefore, product formed is:

Since, -CH₃ group is ortho, para directing the minor product will be

Hence, the option (1) is correct.

y = e^cx
dy/dx = c. e^cx
y' = cy

Explanation:

- Given that f'(2) = 4 and f'(1) = 2
- The derivative of a function represents the rate of change of the function at a specific point.
- Therefore, f'(2) = 4 means that the rate of change of the function at x = 2 is 4.
- Similarly, f'(1) = 2 means that the rate of change of the function at x = 1 is 2.
- To find the value of f(x) when the derivative is given, we need to integrate the derivative function.
- Since the derivative of f(x) is given, we can integrate it to find f(x).
- Integrate f'(x) = 4 with respect to x, we get f(x) = 4x + C (where C is the constant of integration)
- Integrate f'(x) = 2 with respect to x, we get f(x) = 2x + D (where D is the constant of integration)
- Since both expressions represent the same function f(x), we can equate them: 4x + C = 2x + D
- Solving for x, we get x = (D - C) / 2
- Therefore, the answer is B: 4.