List of top Physics Questions

The speed with which the earth have to rotate on its axis so that a person on the equator would weigh \((3/5)^{\text{th}\) as much as present. (Radius of earth = 6400 km)}

For a body moving with relativistic speed if the velocity is doubled, then

Position of a body with acceleration \(\alpha\) is given by \(x = k \alpha^m t^n\), here \(t\) is time. Find the dimension of \(m\) and \(n\)

Due to a force of \((6\hat{i} + 2\hat{j})\ \text{N\) the displacement of a body is \((3\hat{i} - \hat{j})\ \text{m}\), then the work done is}

The plano-convex lens of focal length \(20\ \text{cm}\) and \(30\ \text{cm}\) are placed together to form a double convex lens, the final focal length will be

Angular momentum is conserved

The moment of inertia of a disc of mass \(m\) and radius \(R\) about an axis, which is tangential to the circumference of the disc and parallel to its diameter is

Escape velocity at surface of earth is \(11.2\ \text{km/s}\). Escape velocity from a planet whose mass is the same as that of earth and radius \(1/4\) that of earth, is

A body weighs \(500\ \text{N}\) on the surface of the earth. How much would it weigh half way below the surface of the earth?

An earth satellite \(S\) has orbit radius which is 4 times that of communication satellite \(C\). The period of revolution of \(S\) will be

\(n\) small balls, each of mass \(m\) impinge elastically each second on a surface with a velocity \(u\), then the force experienced by the surface in one second, will be

A circular disc is rotating with angular velocity \(\omega\). If a man standing at the edge of the disc walks towards its centre then the angular velocity of the disc will

An elevator car whose floor to ceiling distance is \(2.7\ \text{m}\) starts ascending with a constant acceleration of \(1.2\ \text{m/s}^2\). \(2\ \text{s}\) after a bolt begins to fall from the ceiling of the car. The free fall time of the bolt is \((g = 9.8\ \text{m/s}^2)\)

A wet open umbrella is held vertical and it whirls about the handle at a uniform rate of 21 revolutions in \(44\ \text{s}\). If the rim of the umbrella is a circle of \(1\ \text{m}\) in diameter and the height of the rim above the floor is \(4.9\ \text{m}\), the locus of the drop is a circle of radius

The moment of inertia of a body about a given axis is \(1.2\ \text{kg·m}^2\). To produce a rotational kinetic energy of \(1500\ \text{J}\) an angular acceleration of \(25\ \text{rad/s}^2\) must be applied for

A running man has half the kinetic energy of that of a boy of half of his mass. The man speeds up by \(1\ \text{m/s}\) so as to have the same kinetic energy as that of the boy. The original speed of the man is

A prism of refractive index \(\sqrt{2}\) has refracting angle of \(60^{\circ}\). At what angle a ray must be incident on it so that it suffers minimum deviation?

Simple pendulum of length \(l\) has a maximum angular displacement \(\theta\). The maximum kinetic energy of the bob is

The radius \(R\) of a soap bubble is doubled under isothermal condition. If \(T\) be the surface tension of soap bubble, the work done in doing so is given by

Radius of orbit of satellite of earth is \(R\). Its kinetic energy is proportional to

Threshold wavelength of a metal is \(4000\ \text{Å}\). If light of wavelength \(3000\ \text{Å}\) irradiates the surface, the maximum kinetic energy of photoelectron is

A body of specific heat \(0.2\ \text{kcal/kg}^\circ\text{C}\) is heated through \(100^\circ\text{C}\). The percentage increase in its mass is

Two similar coils are kept mutually perpendicular such that their centres coincide. At the centre, find the ratio of the magnetic field due to one coil and the resultant magnetic field through both coils, if the same current is flown

A car travelling on a straight track moves with uniform velocity \(v_1\) for some time and with uniform velocity \(v_2\) for the next equal time. The average velocity of the car is

A balloon contains \(1500\ \mathrm{m}^3\) of helium at \(27^{\circ}\mathrm{C}\) and 4 atmospheric pressure. The volume of helium at \(-3^{\circ}\mathrm{C}\) temperature and 2 atmospheric pressure will be