List of top Physics Questions asked in JEE Main

A Carnot engine working between 27°C and 127°C performs 2 kJ of work. The amount of heat rejected is equal to:

Given below are two statements:
Statement I: A truck and a car moving with same kinetic energy are brought to rest by applying brakes which provide equal retarding forces. Both come to rest in equal distance. 
Statement II : A car moving towards east takes a turn and moves towards north, the speed remains unchanged. The acceleration of the car is zero. 
In the light of given statements, choose the most appropriate answer from the options given below.  

An emf of 0.08 V is induced in a metal rod of length 10 cm held normal to a uniform magnetic field of 0.4 T, when moves with a velocity of:

Match List I with List II List I List II A. Spring constant I. (T-1) B. Angular speed II. (MT-2) C. Angular momentum III. (ML2) D. Moment of Inertia IV. (ML2T-1)

	List I		List II
A	Spring constant	I	(T-1)
B	Angular speed	II	(MT-2)
C	Angular momentum	III	(ML2)
D	Moment of Inertia	IV	(ML2T-1)

Choose the correct answer from the options given below:

For a certain organ pipe, the first three resonance frequencies are in the ratio of 1:3:5 respectively. If the frequency of fifth harmonic is 405 Hz and the speed of sound in air is 324 ms^-1 the length of the organ pipe is ___ m.

A hydraulic automobile lift is designed to lift vehicles of mass 5000 kg. The area of cross section of the cylinder carrying the load is 250 cm². The maximum pressure the smaller piston would have to bear is [Assume g = 10 m/s²]:

Glycerine of density 1.25 × 10³ kg m^-3 is flowing through the conical section of pipe. The area of cross-section of the pipe at its ends is 10 cm2 and 5 cm2 and pressure drop across its length is 3 Nm^-2. The rate of flow of glycerine through the pipe is x x10^-5 m3 s^-1. The value of x is____.

For a rolling spherical shell, the ratio of rotational kinetic energy and total kinetic energy is \(\frac{x}{5}\). The value of x is____.

To maintain a speed of 80 km/h by a bus of mass 500 kg on a plane rough road for 4 km distance, the work done by the engine of the bus will be ____KJ. [The coefficient of friction between tyre of bus and road is 0.04].

In an n-p-n common emitter (CE) transistor the collector current changes from 5 m A to 16 mA for the change in base current from 100 μ A and 200 μA , respectively. The current gain of transistor is Options 1. 110 2. 0.9 3. 210 4. 9

A 12.5 eV electron beam is used to bombard gaseous hydrogen at room temperature. The number of spectral lines emitted will be

If a body of mass 5 kg is in equilibrium due to forces \(F_1\), \(F_2\) and \(F_3\). \(F_2\) and\(F_3\) are perpendicular to each other. If \(F_1\) is removed then find the acceleration of the body. Given \(F_2\)=6N and \(F_3\)=8N

A proton with a kinetic energy of 2.0 eV moves into a region of uniform magnetic field of magnitude \(\dfrac{\pi}{2} \times 10^{-3} \text{T}\). The angle between the direction of magnetic field and velocity of proton is 60°. The pitch of the helical path taken by the proton is \_\_\_\ cm.

As shown in the figure, two parallel plate capacitors having equal plate area of 200 cm2 are joined in such a way that a ≠ b. The equivalent capacitance of the combination is x ∈0 F. The value of x is_____.

Two concentric circular coils with radii 1 cm and 1000 cm, and number of turns 10 and 200 respectively are placed coaxially with centers coinciding. The mutual inductance of this arrangement will be _____× 10^-8 H.
(Take, π² = 10)

A metal block of mass m is suspended from a rigid support through a metal wire of diameter 14 mm. The tensile stress developed in the wire under equilibrium state is 7× 10⁵ Nm^-2 . The value of mass m is ___ kg. (Take, g = 9.8 ms-2 and π =\(\frac{ 22}{7}\))

A point object, 'O' is placed in front of two thin symmetrical coaxial convex lenses L₁ and L₂ with focal length 24 cm and 9 cm respectively. The distance between two lenses is 10 cm and the object is placed 6 cm away from lens L₁ as shown in the figure. The distance between the object and the image formed by the system of two lenses is _____ cm.

A body is dropped on ground from a height ‘h₁’ and after hitting the ground, it rebounds to a height ‘h₂’ If the ratio of velocities of the body just before and after hitting ground is \(4\). then percentage loss in kinetic energy of the body is\(\frac{x}{4}\). The value of x is_____.

An electron revolves around an infinite cylindrical wire having uniform linear charge density \(2×10^{–8}\ Cm^{-1}\) in circular path under the influence of attractive electrostatic field as shown in the figure. The velocity of electron with which it is revolving is ____ \(\times 10^6 ms^{-1}\). Given mass of electron = \(9\times10^{-31}\) kg.

A dipole comprises of two charged particles of identical magnitude q and opposite in nature. The mass ‘m’ of the positive charged particle is half of the mass of the negative charged particle. The two charges are separated by a distance ‘l’. If the dipole is placed in a uniform electric field ‘\(\overrightarrow{E}\); such a way that dipole axis makes a very small angle with the electric field, ‘\(\overrightarrow{E}\)'. The angular frequency of the oscillations of the dipole when released is given by.

A rectangular block of mass 5 kg attached to an horizontal spiral spring executes simple harmonic motion of amplitude 1 m and time period 3.14s. The maximum force exerted by spring on block is _____N.