List of top Physics Questions asked in JEE Main

5th harmonic of a closed organ pipe matches with 1st harmonic of an open organ pipe. Find ratio of their lengths.

Detector $D$ moves from $A$ to $B$ and observes that the frequencies differ by $10\ \text{Hz}$. The source is emitting frequency $f_0$ as shown. The speed of the detector is $35$ times less than the speed of sound. Then $f_0$ is:

Ratio of de-Broglie wavelengths of a proton and an alpha particle accelerated through the same potential is:

Following are two lists, list-I contains the types of electromagnetic waves and list-II contains theirs source. Match the entries from list-I to appropriate entries from list-II.

If electric field component is $E = 377\sin(\omega t + kx)$ V/m of an electromagnetic wave and \[ \sqrt{\frac{\mu_0}{\varepsilon_0}} = 377, \] then find the average intensity of the wave (in W/m$^2$):

An electromagnetic wave travelling in a medium has its electric field given by : \(E = 2\sin(2 \times 10^{15}t - 10^7x)\). Find the refractive index of the medium :

Equation of an electromagnetic wave in a medium is given by \[ E = 2\sin\left(2\times 10^{15}t - 10^{7}x\right). \] Find the refractive index of the medium.

Dielectric constant of a medium is 3 and its magnetic permeability \(\mu = 2\mu_0\). Find ratio of velocity of light in vacuum to velocity of light in medium :

A sinusoidal electromagnetic wave is given by \( \vec{E} = 20 \sin \left( \frac{2}{300} x - 10^6 t \right) \) propagating in a non-magnetic material. Dielectric constant of the material is.

If a satellite orbiting the Earth is 9 times closer to the Earth than the Moon, what is the time period of rotation of the satellite? Given rotational time period of Moon = 27 days and gravitational attraction between the satellite and the Moon is neglected.

Three masses m\(_{1}\) = 200 kg, m\(_{2}\) = 300 kg and m\(_{3}\) = 400 kg are kept at the vertices of on equilateral triangle of side 20 m. If the masses are shifted to new configuration such that they are at the vertices of an equilateral triangle of 25 m now. Find the work done in this process :

If initially the force on \(m_0\) is \(F_0\). When the positions of \(4m\) and \(3m\) are interchanged, the force becomes \(F'\). If \[ \frac{F_0}{F'}=\frac{\alpha}{\sqrt{5}}, \] find \(\alpha\).

A planet 'A' having density \( \rho \) and radius \( R \) has escape velocity \( = 10 \, \text{km/sec} \). Find the escape velocity of a planet B having density and radius both 10% that of planet A.

For an object revolving around a planet of mass \( M \) and radius \( R_0 \) at a distance \( r \) from the center of the planet. If area velocity of the object is 10 km/sec. Now if the density of the planet increases by +10% and radius of the planet increases by +10%, then find the new area velocity at the same orbital radius.

A satellite is revolving around a planet in orbit radius of 1.5 R. Additional minimum energy required to transfer the satellite to the new orbit radius of 3R is (G and M are mass of satellite \& planet)

Six charges (four \( +q \), two \( -q \)) are present at a circle of radius \( r \) and centered at the origin as shown. The electric field at the origin is.

Two spheres having equal mass \(m\), charge \(q\), and radius \(R\) are moving towards each other. Both have speed \(u\) at an instant when the distance between their centres is \(4R\). Find the minimum value of \(u\) so that they just touch each other.

Find electric field intensity \( \vec{E} \) at the centre of the circle shown in the figure.

In the following configuration of charges. Find the net dipole moment of the system :

A simple pendulum with a bob (mass \( m \) and charge \( q \)) is in equilibrium in the presence of a horizontal electric field \( E \). Then, the tension in the thread is \( F_1 \). Given \( \frac{F_1}{F_2} = \frac{2}{\sqrt{\alpha}} \), find \( \alpha \).