List of top Physics Questions

The mass of ce¹5N is 15.00011u, mass of ce¹6O is 15.99492u and mp=1.00783u. Determine the binding energy of the last proton of ce¹6O.
The drift velocity of electrons in a silver wire with cross-sectional area 3.14×10⁻6m² carrying a current of 20A is. Atomic weight of Ag = 108, density of silver = 10.5×10³kg m⁻3.
In the Young’s double-slit experiment, the intensity of light at a point on the screen where the path difference is λ/K (where λ is the wavelength of light used). The intensity at a point where the path difference is λ/4 will be:
Kepler’s third law states that the square of period of revolution T of a planet around the sun is proportional to the cube of average distance r between sun and planet i.e. T² = Kr³, where K is constant. If the masses of sun and planet are M and m respectively and as per Newton’s law of gravitation the force of attraction between them is F=(GMm)/(r²), where G is gravitational constant, the relation between G and K is described as:
A string of length ℓ is fixed at both ends. It is vibrating in its 3ʳd overtone with maximum amplitude a. The amplitude at a distance ℓ/3 from one end is:
A deuteron of kinetic energy 50keV is describing a circular orbit of radius 0.5m in a plane perpendicular to a magnetic field B. The kinetic energy of the proton that describes a circular orbit of radius 0.5m in the same plane with the same B is:
The approximate depth of an ocean is 2700m. The compressibility of water is 45.4 × 10⁻11Pa⁻1 and density of water is 10³kg m⁻3. What fractional compression of water is obtained at the bottom of the ocean?
Two spheres of different materials, one with double the radius and one-fourth wall thickness of the other, are filled with ice. If the time taken for complete melting of ice in the larger sphere is 25 minutes and for the smaller one is 16 minutes, the ratio of thermal conductivities of the materials of larger spheres to that of smaller sphere is:
Two wires are made of the same material and have the same volume. However wire 1 has cross-sectional area A and wire 2 has cross-sectional area 3A. If the length of wire 1 increases by Δ x on applying force F, how much force is needed to stretch wire 2 by the same amount?
A radioactive element X converts into another stable element Y. Half-life of X is 2 hours. Initially only X is present. After time t, the ratio of atoms of X and Y is found to be 1:4. Then t, in hours, is:
A bi-convex lens has a radius of curvature of magnitude 20cm. Which one of the following options best describes the image formed of an object of height 2cm placed 30cm from the lens?
What should be the velocity of rotation of earth due to rotation about its own axis so that the weight of a person becomes (3)/(5) of the present weight at the equator. Equatorial radius of earth is 6400km.
The surface charge density of a thin charged disc of radius R is σ. The value of the electric field at the centre of the disc is (σ)/(2varepsilon₀). With respect to the field at the centre, the electric field along the axis at a distance R from the centre of the disc:
The molecules of a given mass of a gas have r.m.s. velocity of 200m s⁻1 at 27^∘C and 1.0×10⁵N m⁻2 pressure. When the temperature and pressure of the gas are respectively 127^∘C and 0.05×10⁵N m⁻2, the r.m.s. velocity of its molecules in m s⁻1 is:
A wire of length $L$ and mass per unit length $6.0 \times 10^{-3} \,kgm^{-1}$ is put under tension of $540\, N$. Two consecutive frequencies that it resonates at are: $420\, Hz$ and $490 \,Hz$. Then $L$ in meters is :
In meter bridge experiment, null point was obtained at a distance \( f \) from left end. The values of resistances in the left and right gaps are doubled and then interchanged. The new position of null point is
A thin metal rod of mass \(M\) and length \(L\) is cut into 4 equal parts by cutting it perpendicular to its length. If moment of inertia of the rod about an axis passing through its centre and perpendicular to its axis is \(I\), then moment of inertia of each part about the similar axis is
Two satellites \(A\) and \(B\) of same mass are revolving round the earth at height \(2R\) and \(3R\) respectively above the surface of the earth. The ratio of kinetic energies of \(A\) to \(B\) will be
For a gas \(\dfrac{R}{C_v} = 0.67\). This gas is made up of molecules which are
For athermanous substances, coefficient of transmission is
A motorcyclist rides in a horizontal circle about a central vertical axis inside a cylindrical chamber of radius \(r\). If the coefficient of friction between the tyres and the inner surface of the chamber is \(\mu\), the minimum speed of motorcyclist to prevent him from skidding is (\(g\) = acceleration due to gravity)
In meter-bridge experiment a resistance of \(18\,\Omega\) is connected in left gap and unknown resistance \(R\) is connected in right gap. The null point is obtained at \(\ell_1\) from left end. If unknown resistance is replaced by \(\left(\frac{R}{3}\right)\Omega\), the null point is obtained at \(1.5\ell_1\). The unknown resistance is
A prism having refractive index \(\sqrt{2}\) and refracting angle \(30^\circ\) has one of the refracting surfaces silvered. The beam of light incident on the other refracting surface will retrace its path, if angle of incidence is \([\sin(\pi/6)=0.5]\)
If a p–n junction diode is reverse biased then
The resultant of two vectors \(\vec{P}\) and \(\vec{Q}\) is \(\vec{R}\). When the direction of \(\vec{Q}\) is reversed, the resultant is given by \(\vec{S}\). Which one of the following is true for vectors \(\vec{R}\) and \(\vec{S}\)?