List of top Physics Questions

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$^2$):
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.
Electric field of an EM wave is given as \(\vec{E} = 54\sin(kz-\omega t)\,\hat{i}\). Then what will be its corresponding magnetic field?
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 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)
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 :
Escape velocity from a planet of radius \(R\) and density \(\rho\) is given as \(10\,\text{km s}^{-1}\). Find the escape velocity from a planet of radius \(\dfrac{R}{10}\) and density \(\dfrac{\rho}{10}\).
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 \(\alpha\).
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 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.
A simple pendulum with bob of mass \(m\) carrying charge \(q\) is in equilibrium in the presence of a horizontal electric field \(E\). Then the tension in the thread is:
(A) Equivalent capacitance is lower than the least of capacitors present in series.
(B) One method of increasing the capacitance is to decrease the distance between plates and increase cross-sectional area.
(C) Electric field inside an isolated capacitor decreases after inserting a dielectric.
(D) Displacement of charge does not happen when a dielectric is inserted in an isolated capacitor because dielectric acts like an insulator.
(E) Energy of an isolated capacitor increases when a dielectric is inserted in the capacitor.
Of the following statements, which are true?
A \(12\,\text{F}\) capacitor is connected to a \(5\,\text{V}\) battery and fully charged. After disconnecting the battery, it is connected in parallel to an uncharged \(6\,\text{F}\) capacitor. Find the final charge on the \(6\,\text{F}\) capacitor.
A rod has uniformly distributed charge $24\,\mu$C and length $10$ cm. Find force on $1\,\mu$C particle placed at a distance $2$ cm from one end of the rod.

Diagram shows three arrangements of dielectric in a capacitor. Arrange the capacitors in increasing order of capacitance between A and B if $K_1>K_2$. 

If the electric potential is \(V = 500\) volts at the point \((10,\,20)\) and the electric field is given by \[ \vec{E} = 10x\,\hat{i} + 5y\,\hat{j}\ \text{N/C}, \] find the potential at the origin.
Three uniformly charged concentric shells are kept as shown in the diagram. Charges on individual shells are as shown. Find the final potential on each shell :
A parallel plate capacitor with plate separation 5 mm is charged by a battery. On introducing a mica sheet of 2 mm while battery is connected, it is found that it draws 25% more charge. The dielectric constant of mica is :
There are two point charges, one at the vertex and the other at the face of a cube as shown. Find the electric flux through the cube.
(I) Gauss Law is defined for inverse square of distance forces.
(II) Work done by uniform electric field on a charge moving in a circle is zero.
(III) Electric field of a point-charge forms concentric circle around it.
(IV) Electric field lines forms closed loop.
Choose correct option(s).
Four charges are kept as shown in the figure. Find magnitude of electric field at point P. P is mid point of line AB.
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.
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.