JEE Main Mock Test - 14 - JEE MCQ

Let there be a spherically symmetric charge distribution with charge density varying as up to r = R and ρ (r) = 0 for r > R, where r is the distance from the origin. The electric field at a distance r (r < r)="" from="" the="" origin="" is="" given="" />

Electromagnetic waves are transverse in nature, is evident by

A car is moving on a straight road. If its engine is delivering constant power, then the distance covered by the car in time t is proportional to

A light spring balance hangs from the hook of the other light spring balance and a block of mass M kg hangs from the former one. Then, the true statement about the scale reading is

Two particles starting from a point on a circle of radius 4 m in a horizontal plane move along the circle in opposite directions with constant speeds of 4 ms^-1 and 6 ms^-1. The particles will collide with each other in

Which of the following represents the Boolean function for the given circuit of gates?

When a system is taken from state i to state f along the path iaf, it is found that Q = 50 cal and W = 20 cal. Along the path ibf, Q = 36 cal. W along the path ibf is

If force F is related with distance x and time t as F = A√x + Bt² , the dimensions of A/B is

A bob is hanging over a pulley inside a car through a string. The second end of the string is in the hand of a person standing in the car. The car is moving with constant acceleration aa directed horizontally as shown in the figure. Another end of the string is pulled with constant acceleration a vertically. The tension in the string is equal to :

A disc of mass M and radius R is rolling with angular speed ωω on a horizontal plane as shown. The magnitude of angular momentum of the disc about the origin O is

The magnitude of the maximum acceleration is π times that of the maximum velocity of a simple harmonic oscillator. The time period of the oscillator in seconds is

An object of specific gravity ρ is hung from a thin steel wire. The fundamental frequency for transverse standing waves in the wire is 300 Hz. The object is immersed in water, so that one half of its volume is submerged. The new fundamental frequency (in Hz) is

One mole of ideal gas goes through process then change in temperature of the gas when volume changes from V = 1 m³ to 2 m³ is:

A very long straight wire carries a current I. At the instant when a charge +Q at point P has velocity , as shown, the force on the charge is

The ratio of the volume occupied by an atom to the volume of the nucleus is

Energy from the sun falls on the earth at a rate of 1353 W/m², which is known as solar constant, i.e., the power incident per unit area per second at the top of atmosphere. Find the r.m.s values of the electric and magnetic fields in the sunlight reaching the top of the atmosphere.

The effect on the interference fringes if the monochromatic source is replaced by a source of white light would be:

A Carnot engine takes 3 × 10⁶ cal of heat from a reservoir at 627°C and gives it to a sink at 27°C. The work done by the engine is W × 106 J. State the value of W. (Nearest integer)

In a series resonant LCR circuit, the voltage across R is 100 volts and R = 1 k Ω with C = 2 μF. The resonant frequency is 200 rad/s. At resonance, the voltage across L, in Volt, is

A boy weighing 50 kg eats bananas.The energy content of banana is 1000 cal. If this energy is used to lift the boy from ground, then find the height (in cm) through which he is lifted. Take g = 10 m s⁻² mechanical equivalent of heat = 4.2 J cal⁻¹

The magnification produced by the objective lens and the eye lens of a compound microscope are 25 and 6 respectively. The magnification of this microscope is 50n, then find nn.

A simple pendulum has a time period T₁ when on the earth’s surface, and T₂ when taken to a height R above the earth’s surface, where R is the radius of the earth. The value of T₂/T₁ is

The radioactive isotope which is used in the treatment of cancer, can be made by (n, p) reaction. What is the target nucleus for this reaction?

The bond lengths and bond angles in the molecules of methane, ammonia and water are given below:

This variation in bond angle is a result of

(i) the increasing repulsion between hydrogen atoms as the bond length decreases

(ii) the number of non-bonding electron pairs in the molecule

(iii) a non-bonding electron pair having a greater repulsive force than a bonding electron pair

For a first order reaction A P, the temperature (T) dependent rate constant (k) was found to follow the equation log

The pre-exponential factor A and the activation energy E_a respectively are

Directions: The following question has four choices, out of which ONLY ONE is correct.

Wavelengths of X-ray lines of Mg and Cr are 0.987 nm and 0.229 nm, respectively. The values of the constants 'a' and 'b' for this series should respectively be

Identify the incorrect statement.