List of top Physics Questions

The electric field at a point on the axis of a uniformly charged ring of radius R at a distance x from its center is given by: \[ E = \frac{1}{4\pi\epsilon_0} \cdot \frac{2\pi kQx}{(x^2 + R^2)^{3/2}}. \] If x = 2R, what is the magnitude of the electric field?
An oxygen cylinder of volume 30 litre has 18.20 moles of oxygen. After some oxygen is withdrawn from the cylinder, its gauge pressure drops to 11 atmospheric pressure at temperature \(27^\circ\)C. The mass of the oxygen withdrawn from the cylinder is nearly equal to: [Given, \(R = \frac{100}{12} \text{ J mol}^{-1} \text{K}^{-1}\), and molecular mass of \(O_2 = 32 \text{ g/mol}\), 1 atm pressure = \(1.01 \times 10^5 \text{ N/m}^2\)]
Which of the following is the correct unit for electric charge?
A car accelerates from rest to a speed of 20 m/s in 10 seconds. What is its acceleration?

Which of the following is the correct electronic configuration for \( \text{Oxygen (O)} \)?

The number of significant figures in the measurement 0.00456 is:
Which of the following is an example of a scalar quantity?
Calculate the electric field at a point due to a uniformly charged spherical shell.
Let \( \lambda_e \), \( \lambda_p \), and \( \lambda_d \) be the wavelengths associated with an electron, a proton, and a deuteron, all moving with the same speed. Then the correct relation between them is:
A source supplies heat to a system at the rate of 1000 W. If the system performs work at a rate of 200 W, what is the rate at which internal energy of the system increases?
A simple pendulum performing small oscillations at a height R above Earth's surface has a time period of \(T_1 = 4\) s. What would be its time period at a point which is at a height \(2R\) from Earth's surface?
The escape velocity from the surface of a planet is \(v_e\). What will be the escape velocity from a planet whose mass and radius are twice that of the original planet?
A simple pendulum has a time period of 2 s on Earth's surface. What is its time period at a height equal to the Earth's radius (R)? (Acceleration due to gravity at height h is \( g_h = \frac{g}{(1 + h/R)^2} \)).
A force of 49 N acts tangentially at the highest point of a sphere (solid of mass 20 kg) kept on a rough horizontal plane. If the sphere rolls without slipping, then the acceleration of the center of the sphere is:
A block of mass 5 kg is placed on a frictionless surface and a force of 20 N is applied horizontally. What is the acceleration of the block?
The equivalent resistance between points A and B in a circuit with two resistors of 6 \(\Omega\) each connected in parallel is:
A galvanometer has resistance \( G = 100 \, \Omega \) and shows full-scale deflection at \( I_q = 1 \, \text{mA} \). To convert it into a voltmeter of range 5 V, what resistance should be connected in series?
In a mixture of gases, the average number of degrees of freedom per molecule is 6. If the rms speed of the molecule is \(c\), what is the velocity of sound in the gas?

Which one out of the following materials is \(\textit{not}\) paramagnetic
 

Read the following paragraphs and answer the questions that follow.
A parallel plate capacitor consists of two conducting plates kept generally parallel to each other at a distance. When the capacitor is charged, the charge resides on the inner surfaces of the plates and an electric field is set up between them. Thus, electrostatic energy is stored in the capacitor.
The figure shows three large square metallic plates, each of side ‘L’, held parallel and equidistant from each other. The space between P1 and P2, and P2 and P3 is completely filled with mica sheets of dielectric constant ‘K’.
The plate P2 is connected to point A and the other plates P1 and P3 are connected to point B. Point A is maintained at a positive potential with respect to point B and the potential difference between A and B is V .
A parallel plate capacitor consists of two conducting plates kept generally

A hydrogen atom consists of an electron revolving in a circular orbit of radius r with certain velocity v around a proton located at the nucleus of the atom. The electrostatic force of attraction between the revolving electron and the proton provides the requisite centripetal force to keep it in the orbit. According to Bohr’s model, an electron can revolve only in certain stable orbits. The angular momentum of the electron in these orbits is some integral multiple of \(\frac{h}{2π}\), where h is the Planck’s constant.

Differentiate between magnetic flux through an area and magnetic field at a point.
Monochromatic light of green color is used in Young’s double slit experiment and an interference pattern is observed on a screen. If the green light is replaced by red monochromatic light of the same intensity, how will the fringe width of the interference pattern be affected? Justify your answer.
The figure shows the plot of magnitude of induced emf (\( \varepsilon \)) versus the rate of change of current in two coils ‘1’ and ‘2’. Which coil has a greater value of self-inductance and why?
plot of magnitude of induced emf
Write the conditions under which two light waves originating from two coherent sources can interfere each other (i) constructively, and (ii) destructively, in terms of wavelength. Can these be applied for two lights originating from two sodium lamps? Give reason.