List of top Physics Questions asked in JEE Main

A conducting circular loop of area 1.0 m$^2$ is placed perpendicular to a magnetic field which varies as B = sin(100t) Tesla. If the resistance of the loop is 100 $\Omega$, then the average thermal energy dissipated in the loop in one period is_________ J.

A point source is kept at the center of a spherically enclosed detector. If the volume of the detector is increased by 8 times, the intensity will

Two strings (A, B) having linear densities $\mu_A = 2 \times 10^{-4}$ kg/m and, $\mu_B = 4 \times 10^{-4}$ kg/m and lengths $L_A = 2.5$ m and $L_B = 1.5$ m respectively are joined. Free ends of A and B are tied to two rigid supports C and D, respectively creating a tension of 500 N in the wire. Two identical pulses, sent from C and D ends, take time $t_A$ and $t_B$, respectively, to reach the joint. The ratio $t_A/t_B$ is:

A moving coil galvanometer of resistance $100\,\Omega$ shows a full scale deflection for a current of $1\,\text{mA}$. The value of resistance required to convert this galvanometer into an ammeter, showing full scale deflection for a current of $5\,\text{mA}$, is ________ $\Omega$.

A 1 m long metal rod AB completes the circuit as shown in figure. The area of circuit is perpendicular to the magnetic field of 0.10 T. If the resistance of the total circuit is 2 $\Omega$ then the force needed to move the rod towards right with constant speed (v) of 1.5 m/s is _____ N.

Identify the correct truth table of the given logic circuit.

The given circuit works as:

In a double slit experiment the distance between the slits is 0.1 cm and the screen is placed at 50 cm from the slits plane. When one slit is covered with a transparent sheet having thickness t and refractive index n(=1.5), the central fringe shifts by 0.2 cm. The value of t is_________ cm.

If an alpha particle with energy 7.7 MeV is bombarded on a thin gold foil, the closest distance from nucleus it can reach is_____ m.
(Atomic number of gold = 79 and $\frac{1}{4\pi\epsilon_0}=9\times10^{9}$ SI units)

A flexible chain of mass $m$ hangs between two fixed points at the same level. The inclination of the chain with the horizontal at the two points of support is $30^\circ$. Considering the equilibrium of each half of the chain, the tension of the chain at the lowest point is ________.

In a vernier callipers, 50 vernier scale divisions are equal to 48 main scale divisions. If one main scale division = 0.05 mm, then the least count of the vernier callipers is ________ mm.

Two identical thin rods of mass M kg and length L m are connected as shown in figure. Moment of inertia of the combined rod system about an axis passing through point P and perpendicular to the plane of the rods is $\frac{x}{12} ML^2$ kg m$^2$. The value of x is ______ .

A collimated beam of light of diameter 2 mm is propagating along the x-axis. The beam is required to be expanded into a collimated beam of diameter 14 mm using a system of two convex lenses. If the first lens has focal length 40 mm, then the focal length of the second lens is_____ mm.

10 mole of oxygen is heated at constant volume from 30 $^{\circ}$C to 40 $^{\circ}$C. The change in the internal energy of the gas is_____ cal.
(The molecular specific heat of oxygen at constant pressure, $C_p=7$ cal/mol $^{\circ}$C and $R=2$ cal/mol $^{\circ}$C.)

Two identical circular loops $P$ and $Q$ each of radius $r$ are lying in parallel planes such that they have common axis. The current through $P$ and $Q$ are $I$ and $4I$ respectively in clockwise direction as seen from $O$. The net magnetic field at $O$ is:

The fifth harmonic of a closed organ pipe is found to be in unison with the first harmonic of an open pipe. The ratio of lengths of closed pipe to that of the open pipe is $ \frac{5}{x} $. The value of $ x $ is ________.

In case of vertical circular motion of a particle by a thread of length $ r $, if the tension in the thread is zero at an angle $30^\circ$ as shown in the figure, the velocity at the bottom point (A) of the vertical circular path is ( $ g $ = gravitational acceleration ).

Distance between an object and three times magnified real image is 40 cm. The focal length of the mirror used is ________ cm.

The velocity ($v$) – distance ($x$) graph is shown in the figure. Which graph represents acceleration ($a$) versus distance ($x$) variation of this system?

The binding energy for the following nuclear reactions are expressed in MeV.
\[ {}^{3}_{2}\text{He} + {}^{1}_{0}\text{n} \rightarrow {}^{4}_{2}\text{He} + 20 \text{ MeV} \] \[ {}^{4}_{2}\text{He} + {}^{1}_{0}\text{n} \rightarrow {}^{5}_{2}\text{He} - 0.9 \text{ MeV} \] If $ X_3, X_4, X_5 $ denote the stability of $ {}^{3}_{2}\text{He}, {}^{4}_{2}\text{He} $ and $ {}^{5}_{2}\text{He} $, respectively, then the correct order is:

A small metallic sphere of diameter 2 mm and density 10.5 g/cm$^3$ is dropped in glycerine having viscosity 10 Poise and density 1.5 g/cm$^3$ respectively. The terminal velocity attained by the sphere is ___ cm/s. ($\pi = \frac{22}{7}$ and $g = 10$ m/s$^2$)

Match the LIST-I with LIST-II:

List-I		List-II
A.	Radio-wave	I.	is produced by Magnetron valve
B.	Micro-wave	II.	due to change in the vibrational modes of atoms
C.	Infrared-wave	III.	due to inner shell electrons moving from higher energy level to lower energy level
D.	X-ray	IV.	due to rapid acceleration of electrons

Choose the correct answer from the options given below:

Density of water at $4^\circ$C and $20^\circ$C are $1000\,\text{kg/m}^3$ and $998\,\text{kg/m}^3$ respectively. The increase in internal energy of $4\,\text{kg}$ of water when it is heated from $4^\circ$C to $20^\circ$C is ___ J.
(Specific heat capacity of water $= 4.2\,\text{J g}^{-1}\text{K}^{-1}$ and atmospheric pressure $=10^5\,\text{Pa}$)

A short bar magnet placed with its axis at $30^\circ$ with an external magnetic field of $800$ Gauss experiences a torque of $0.016\,\text{N m}$. The work done in moving it from most stable to most unstable position is $\alpha \times 10^{-3}\,\text{J}$. The value of $\alpha$ is ___.

Sixty four rain drops of radius $1\,\text{mm}$ each falling down with a terminal velocity of $10\,\text{cm/s}$ coalesce to form a bigger drop. The terminal velocity of the bigger drop is ___ cm/s.