List of top Physics Questions asked in JEE Main

In a photoelectric experiment, frequency $f = 1$.$5f_0$ ($f_o$: threshold frequency). If the frequency of light is changed to $\frac{f}{2}$, then photocurrent becomes (intensity of light has doubled)

Unpolarised light incident on transparent glass at incident angle 60°. If reflected ray is completely polarized, then angle of refraction is

If the current through an incandescent lamp decreases by 20%, how much change will be there in its illumination?

Consider the circuit shown : The ammeter reads 0.9 A. Value of R is

In a given circuit, an ideal battery is connected with four resistances as shown. Find current $i$ as mentioned in the diagram.

Consider a rod moving in a magnetic field as shown:

The induced emf across the ends of the rod is

Alternating voltage and current in circuit is given as $V = (100 \;sin \;ωt)$ volt
$I = 100\;sin\bigg(ωt+\frac{π}{3}\bigg)mA$
Find average power dissipated in circuit.

Two charged particles A and B have charge q each while masses are $m_1$ & $m_2$. Both have the same velocity v and enter into a transverse magnetic field B such that their radii are $r_1$ & $r_2$. Then the ratio $m_1 : m_2$ is

In a simple pendulum of length 10 m, the string is initially kept horizontal and the bob is released. 10% of energy is lost till the bob reaches the lowest position. Then find the speed of the bob at the lowest position.

Two forces $F_1$ and $F_2$ are applied on two rods $P$ and $Q$ of same materials such that elongation in rods are same. If ratio of their radii is $x : y$ and ratio of length is $m : n$, then ratio of $F_1 : F_2$ is

A uniform wire has length L and radius r. It is acted on by a force F as shown. The elongation is l. If F and r are both halved, the new elongation will be :

The truth table for the combination of logical gates

Find the ratio of the charge on $4$ $µF$ to that on $2$ $µF$ in steady state.

A ball of mass $120$ $g$ moving with initial velocity $25 \;m/s$ is stopped by an external force $F$ in $0.15$ $sec$. Find value of $F$ in newton :

Find the number of significant digits in the value 10.05

Two trains run on North-South parallel tracks. Train A moves with velocity 20 m/s towards North and train B moves with velocity 30 m/s towards South. Then find the velocity of train B with respect to train A

Two particles each of mass $2$ kg are places as shown in $x→ y$ plane. If the distance of centre of mass from origin is $\frac{4\sqrt 2}{x}$ find $x$ :

The length of a seconds pendulum if it is placed at height $2R$ from the surface of the earth (R: radius of earth) is $\frac{10}{xπ^2}$ $m$. Find $x$

If the mass defect in a nuclear reaction is $0.4$ $gm$ then find the $Q$ value of the reaction.

Potential energy function corresponding to conservative force is given as $U(x, y, z) = \frac{3x^2}{2} + 5y + 6z$ then the force at $x = 6$ is $pN$. The value of $p$ upto $2$ its nearest integral value is

A thin liquid film formed between a U-shaped wire and a light slider supports a weight of $1.5 \times 10^{-2}$ $N$. The length of the slider is $30\ cm$ and its weight negligible. The surface tension of the liquid film is -

A particle moves in a circular path with uniform speed v. When it turns by 90°, find ratio of $\frac{v}{<\overrightarrow{v}>}$?

In an Isothermal change, the change in pressure and volume of a gas can be represented for three different temperature $T3 > T2 > T1$ as :

The ratio of powers of two motors is $\frac{3\sqrt x}{\sqrt x+1}$, that are capable of raising 300 kg water in 5 minutes and 50 kg water in 2 minutes respectively from a well of 100 m deep. The value of x will be

A hypothetical gas expands adiabatically such that its volume changes from 08 litres to 27 litres. If the ratio of final pressure of the gas to initial pressure of the gas is $\frac{16}{B 1}$. Then the ratio of $\frac{C p}{C v}$ will be