List of top Physics Questions asked in JEE Main

Two 10 cm long, straight wires, each carrying a current of 5 A are kept parallel to each other. If each wire experienced a force of 10^–5 N, then separation between the wires is _____ cm.

A singly ionized magnesium atom (A=24) ion is accelerated to kinetic energy 5keV and is projected perpendicularly into a magnetic field B of the magnitude 0.5 T. The radius of path formed will be ________ cm.

Two long current carrying conductors are placed parallel to each other at a distance of 8 cm between them. The magnitude of magnetic field produced at mid-point between the two conductors due to current flowing in them is 30 μT. The equal current flowing in the two conductors is:

Given below are two statements:

Statement I: The electric force changes the speed of the charged particle and hence changes its kinetic energy; whereas the magnetic force does not change the kinetic energy of the charged particle.
Statement II: The electric force accelerates the positively charged particle perpendicular to the direction of electric field. The magnetic force accelerates the moving charged particle along the direction of magnetic field.

In the light of the above statements, choose the most appropriate answer from the options given below:

A proton and an alpha particle of the same velocity enter in a uniform magnetic field which is acting perpendicular to their direction of motion. The ratio of the radii of the circular paths described by the alpha particle and proton is

A cyclotron is used to accelerate protons.If the operating magnetic field is 1.0 T and the radius of the cyclotron ‘dees’ is 60 cm,the kinetic energy of the accelerated protons in MeV will be
$[Use\ m_p = 1.6×10^{-27}\ kg, e = 1.6×10^{-19}C]$

In young's double slit experiment, the fringe width is $12\, mm$ If the entire arrangement is placed in water of refractive index $\frac{4}{3}$, then the fringe width becomes (in $mm$ )

The two light beams having intensities $I$ and $9I$ interfere to produce a fringe pattern on a screen. The phase difference between the beams is $\frac {\pi}{2}$ at point P and $\pi$ at point Q. Then the difference between the resultant intensities at P and Q will be:

Two coherent sources of light interfere. The intensity ratio of two sources is 1 : 4. For this interference pattern if the value of
$\frac{I_{max}+I_{min}}{I_{max}-I_{min}}$is equal to $\frac{2α+1}{β+3},$
then α/β will be

Two beams of light having intensities I and 4I interfere to produce a fringe pattern on a screen. The phase difference between the two beams are π/2 and π/3 at points A and B, respectively. The difference between the resultant intensities at the two points is xI. The value of x will be ___.

A light ray is incident at an incident angle θ₁on the system of two plane mirrors M₁ and M₂ having an inclination angle 75° between them (as shown in figure).
After reflecting from mirror M₁ it gets reflected back by the mirror M₂ with an angle of reflection 30°. The total deviation of the ray will be ________ degree.

A light ray is incident, at an incident angle θ1

For a specific wavelength 670 nm of light from a galaxy moving with velocity ν, the observed wavelength is 670.7 nm. The value of ν is

The stopping potential for photoelectrons emitted from a surface illuminated by light of wavelength 6630 Å is 0.42 V. If the threshold frequency is x × 10¹³/s, where x is ____ (nearest integer).
(Given, speed of light = 3 × 10⁸ m/s, Planck’s constant = 6.63 × 10^–34 Js)

A beam of monochromatic light is used to excite the electron in $Li^{++}$ from the first orbit to the third orbit. The wavelength of monochromatic light is found to be $x × 10^{–10}$ m. The value of $x$ is _____ .[Given $hc = 1242$ eV nm]

An npn transistor with current gain $β = 100$ in common emitter configuration is shown in the figure. The output voltage of the amplifier will be

In the following circuit, the correct relation between output (Y) and inputs A and B will be:

For using a multimeter to identify diode from electrical components, choose the correct statement out of the following about the diode:

Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R.

Assertion A :n-p-n transistor permits more current than a p-n-p transistor.
Reason R: Electrons have greater mobility as a charge carrier.

Choose the correct answer from the options given below:

A potential barrier of 0.4 V exists across a p-n junction. An electron enters the junction from the n-side with a speed of 6.0 × 10⁵ms^–1. The speed with which electrons enters the p side will be
$\frac{x}{3} × 10^5$ ms^-1
the value of x is _________.
(Give mass of electron = 9 × 10^–31 kg, charge on electron = 1.6 × 10^–19 C)

Two long parallel conductors $S_1$ and $S_2$ are separated by a distance $10$ cm and carrying currents of $4$ A and $2$ A respectively. The conductors are placed along x-axis in X–Y plane. There is a point P located between the conductors (as shown in figure). A charge particle of $3π$ coulomb is passing through the point P with velocity $\overrightarrow v=(2\hat i+3\hat j)$ m/s; where $\hat i$ and $\hat j$ represents unit vector along x & y axis respectively. The force acting on the charge particle is $4π×10^{−5}(−x\hat i+2\hat j)N$. The value of x is:
The conductors are placed along x-axis in X–Y plane. There is a point P located between the conductors

Identify the solar cell characteristics from the following options :

$B_X$ and $B_Y$ are the magnetic field at the centre of two coils of two coils $X$ and $Y$ respectively, each carrying equal current If coil $X$ has $200$ turns and $20\, cm$ radius and coil $Y$ has $400$ turns and $20 \,cm$ radius, the ratio of $B_X$ and $B_Y$ is

Given below are two statements: One is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): In an uniform magnetic field, speed and energy remains the same for a moving charged particle.
Reason (R): Moving charged particle experiences magnetic force perpendicular to its direction of motion.

A long solenoid carrying a current produces a magnetic field B along its axis. If the current is doubled and the number of turns per cm is halved, the new value of magnetic field will be equal to

The magnetic field at the centre of a circular coil of radius r, due to current I flowing through it, is B. The magnetic field at a point along the axis at a distance $\frac{r}{2}$ from the centre is :