List of top Physics Questions

The image of an object formed on the retina of the eye is
The hysteresis cycle for the material of a permanent magnet is
The half life of a radioactive substance is $30$ days. What is the time taken to disintegrate to $3/4^{th}$ of its original mass?
The greatest and least resultant of two forces acting at a point are 29 Kg wt. and 5, Kg wt. respectively. If each force is increased by 3 Kg w t the magnitude of the resultant of hew forces acting at right angles to each other is.
The graph for photoelectric effect, which is a straight line will be between
The force per unit charge is known as
The frequency of a particle executing simple harmonic motion is 10 hertz. The frequency of variation of its kinetic energy is
The external and internal radius of a hollow cylinder are measured to be $(4.23 \,\pm \,0.01)\, cm$ and $(3.89 \,\pm \, 0.01) \,cm$, respectively. The thickness of the wall of the cylinder is
The extinct humans who lived $1,00,000$ to $40,000$ years ago, in East and Central Asia, used hides to protect their bodies and had brain capacity of $1400 \,c.c.$ were
The expression for the induced emf contains a negative sign $\left( \xi=-\frac{d\phi}{dt}\right)$. The significance of the negative sign is given by the statement
The essential conditions for observing Fresnel class of diffraction is
The escape velocity of a body from the earth depends on (i) the mass of the body. (ii) the location from where it is projected. (iii) the direction of projection. (iv) the height of the location from where the body is launched.
The escape velocity of a body depends upon its mass as
The electrostatic potential inside a charged spherical ball is given by $\phi = ar^2 + b$ where r is the distance from the centre a, b are constants. Then the charge density inside the ball is
The electric field strength due to a circular loop of charge of radius $R$ and linear density of charge $\lambda$ at its centre is proportional to :
The electrical conductivity of semiconductors :
The electric field components in the given figure are $E_x = \alpha x^{1/2}$, $E_y = E_z = 0$ in which $\alpha = 800\, N\, C^{-1}\, m^{-1/2}$. The charge within the cube if net flux through the cube is $1.05\, N\, m^2\,C^{-1}$ (assume $a = 0.1\, m$)
The electric field intensity at a point $P$ due to point charge $q$ kept at point $Q$ is $24 \,N \,C^{-1}$ and the electric potential at point $P$ due to same charge is $12\, J \,C^{-1}$. The order of magnitude of charge $q$ is
The electric field strength at a distance r from a charge q is E. What will be electric field strength if the distance of the observation point is increased to 2 r?
The electric current passing through a metallic wire produces heat because of
The electric charge, in uniform motion, produces
The edge of an aluminium cube is $10 \,cm$ long. One face of the cube is firmly fixed to a vertical wall. $A$ mass of $100 \,kg$ is then attached to the opposite face of the cube. The vertical deflection of this face is (Shear modulus of aluminium = $25 GPa$, $g = 10\, m$ $s^{-2}$)
The earth moves in an elliptical orbit with the sun S at one of foci as shown in the figure. Its rotational kinetic energy is maximum at the point
The dynamic lift of an aeroplane is based on
The distance of distinct vision of a person is 50 cm. He wants to read a book place at 25 cm. What should be the focal length of the spectacles?