List of top Physics Questions

A particle of mass $m$ moves in a circular orbit under the central potential field, $U(r) = -\frac{C}{r}$, where $C$ is a positive constant. The correct radius – velocity graph of the particle's motion is:

The radius of a sphere is measured to be (7.50 ± 0.85) cm. Suppose the percentage error in its volume is x. The value of x, to the nearest integer, is __________.

A galaxy is moving away from the earth at a speed of 286 kms$^{-1}$. The shift in the wavelength of a redline at 630 nm is x $\times 10^{-10}$ m. The value of x, to the nearest integer, is ________. [Take the value of speed of light c, as 3 $\times 10^8$ ms$^{-1}$]

A ball of mass 4 kg, moving with a velocity of 10 ms$^{-1}$, collides with a spring of length 8 m and force constant 100 Nm$^{-1}$. The length of the compressed spring is x m. The value of x, to the nearest integer, is __________.

A TV transmission tower antenna is at a height of 20 m. Suppose that the receiving antenna is at. (i) ground level (ii) a height of 5 m. The increase in antenna range in case (ii) relative to case (i) is n%. The value of n, to the nearest integer, is __________.

Two wires of same length and thickness having specific resistances 6 $\Omega$ cm and 3 $\Omega$ cm respectively are connected in parallel. The effective resistivity is $\rho \Omega$ cm. The value of $\rho$, to the nearest integer, is __________.

A plane electromagnetic wave propagating along y-direction can have the following pair of electric field ($\vec{E}$) and magnetic field ($\vec{B}$) components:

The decay of a proton to neutron is:

An infinite number of point charges, each carrying 1 µC charge, are placed along the y-axis at y = 1 m, 2 m, 4 m, 8 m ............ . The total force on a 1 C point charge, placed at the origin, is x $\times 10^3$ N. The value of x, to the nearest integer, is ________. [Take $\frac{1}{4\pi\epsilon_0} = 9 \times 10^9$ Nm²/C²]

The time taken for the magnetic energy to reach 25% of its maximum value in an LR circuit is:

A proton and an $\alpha$-particle enter into a magnetic field at right angles. The ratio of the radii of trajectory of proton to that of $\alpha$-particle is 2 : 1. The ratio of $K_p : K_{\alpha}$ is:

For an adiabatic expansion of an ideal gas, the fractional change in its pressure is equal to (where $\gamma$ is the ratio of specific heats):

An ideal gas in a cylinder is separated by a piston in such a way that the entropy of one part is $S_1$ and that of the other part is $S_2$. Given that $S_1>S_2$. If the piston is removed then the total entropy of the system will be:

In a series LCR circuit, the inductive reactance ($X_L$) is 10 $\Omega$ and the capacitive reactance ($X_C$) is 4 $\Omega$. The resistance (R) in the circuit is 6 $\Omega$. The power factor of the circuit is:

The correct relation between $\alpha$ (ratio of $I_C$ to $I_E$) and $\beta$ (ratio of $I_C$ to $I_B$) of a transistor is:

The angular momentum of a planet of mass $M$ moving around the sun in an elliptical orbit is $\vec{L}$. The magnitude of the areal velocity of the planet is:

The function of time representing a simple harmonic motion with a period of $\frac{\pi}{\omega}$ is:

Which of the following statements are correct?
(A) Electric monopoles do not exist whereas magnetic monopoles exist.
(B) Magnetic field lines due to a solenoid at its ends and outside cannot be completely straight and confined.
(C) Magnetic field lines are completely confined within a toroid.
(D) Magnetic field lines inside a bar magnet are not parallel.
(E) χ = -1 is the condition for a perfect diamagnetic material, where χ is its magnetic susceptibility.
Choose the correct answer from the options given below:

The speed of electrons in a scanning electron microscope is $1 \times 10^7$ ms⁻¹. If the protons having the same speed are used instead of electrons, then the resolving power of scanning proton microscope will be changed by a factor of:

If the angular velocity of earth's spin is increased such that the bodies at the equator start floating, the duration of the day would be approximately: [Take $g = 10$ ms⁻², $R = 6400 \times 10^3$ m, $\pi = 3.14$]

Consider a uniform wire of mass $M$ and length $L$. It is bent into a semicircle. Its moment of inertia about a line perpendicular to the plane of the wire passing through the centre is:

Consider a sample of oxygen behaving like an ideal gas. At 300 K, the ratio of root mean square (rms) velocity to the average velocity of gas molecule would be: (Molecular weight of oxygen is 32 g/mol; R = 8.3 J K⁻¹ mol⁻¹)

An object of mass $m_1$ collides with another object of mass $m_2$, which is at rest. After the collision the objects move with equal speeds in opposite direction. The ratio of the masses $m_2 : m_1$ is:

In connection with the circuit drawn below (assuming a Zener diode circuit with $V_z=10V$, $R_s=500\Omega$, $R_L=2k\Omega$, $V_{in}=15V$), the value of current flowing through 2 kΩ resistor is _________ × 10⁻⁴ A.

In the given figure, energy levels of H-atom are shown. Transitions A ($n=\infty \to 1$), B ($n=4 \to 2$), C ($n=4 \to 3$) represent :