List of top Physics Questions

A black body emits radiation of maximum intensity of wavelength '\(λ\)' at temperature 'T' K. Its corresponding wavelength at temperature \((2.5T)\) K will be
The excess pressure inside the first soap bubble is three times that inside the second soap bubble. The ratio of the volume of the first soap bubble to the volume of the second soap bubble is
Two soap bubbles, A and B, have radii in the ratio \(3:2\). The excess pressure inside the bubble A to that of B is in the ratio
When a capillary tube of radius 'r' is immersed in water, rise of water is upto height 'h'. The mass of water in capillary tube is 'm'. When another capillary tube of radius 'xr' is immersed in water, the mass of water that will rise in this tube is
A mass tied to a string is whirled in a horizontal circular path with a constant angular velocity and its angular momentum is 'L'. If the length of the string is now halved, keeping angular velocity same then the angular momentum will be
A machine gun fires a bullet of mass 40g with a speed of \(600\text{ ms}^{-1}\). The person holding the gun can bare maximum force of 168N on it. The number of bullets that can be fired from the gun per second is
Radius of gyration of a thin uniform circular disc about the axis passing through its centre and perpendicular to its plane is \(K_c\). Radius of gyration of the same disc about a diamter of the disc is \(K_d\). the ratio \(K_d:K_c\) is
Two planets A and B are orbiting around the sun. The distances of the two planets A and B from the sun are \(r_A\) and \(r_B\) respectively. Also \(r_B = 225\,r_A\). If the orbital speed of the planet A is 'V' then the orbital speed of planet B will be
A solid sphere of radius R and mass M is rotating about its diameter. The moment of intertia of the solid sphere rotating about an axis at a distance \(\frac{R}{3}\) from the centre and parallel to that diameter is
There are two vectors \(\overset{⃗}{A} = 6\hat{i}+9\hat{j}-\hat{k}\) and \(\overset{⃗}{B} = 2\hat{i}+3\hat{j}-p\hat{k}\) which have the same direction. The value of 'p' is
A force 'F' is applied on a square plate of side 'L'. If the percentage error in determining 'L' is 3% and that in 'F' is 2% then the percentage error in determining the pressure is
A ball P is projected at an angle of \(60^{\circ}\) with the vertical with certain initial speed. Another ball Q of the same mass as that of ball P is projected vertically upwards with the same initial speed as that of P. At the highest point, the ratio of potential energy of ball P to that of ball Q is
\((sin30^{\circ} = 0.5)\)
The orbital magnetic moment \((m_{orb})\) of a revolving electron around the nucleus varies with the principal quantum number (\(n\)) as
When the Zener diode is used as a voltage regulator, it is connected in
The half-life of the isotope \(_{11}\text{Na}^{24}\) is 15 hr. How much time does it take for \((\frac{7}{8})^{\text{th}}\) of a sample of this isotope to decay ?
In the circuit shown in figure all the three diodes D1, D2, D3 have forward resistance \(50 \Omega\) each and infinite backward resistance. If the battery voltage is 5V, the current through \(100 \Omega\) resistance is
To get the truth table shown from the following logic circuit, the gate G should be
The kinetic energy of a free electron increases to 3 times the previous K.E. The ratio of new de-Broglie wavelength to previous de-Broglie wavelength is
For wavelength of visible radiation of Hydrogen spectrum, Balmer gave an equation as \(λ = \frac{xm^2}{m^2-4}\), where m is the integer value. The value of x in terms of Rydberg's constant R is
A lens of refractive index '\(μ\)' has focal length '\(f\)'. When the lens is immersed in a liquid of refractive index '\(μ_0\)', its focal length becomes '\(f_0\)'. Then '\(f_0\)' is given by
Photoelectric emission is observed from a metallic surface for frequencies \(ν_1\) and \(ν_2\) of the incident light rays (\(ν_1 > ν_2\)). If the ratio of maximum value of kinetic energy of the photoelectron emitted in first case to that in second case 3 : K, then the threshold frequency of the metallic surface is
In a single slit diffraction experiment, for wavelength '\(λ\)', half angular width of the principal maxima is '\(θ\)'. Also for wavelength of light '\(pλ\)', the half angular width of the principal maxima is '\(qθ\)'. The ratio of the half angular widths of the first secondary maxima in the first case to second case will be
In Young's double slit experiment, width of the second slit is double the width of first slit, consequently the amplitude of the light from two slits. '\(I_m\)' is the maximum intensity. The resultant intensity '\(I\)' when they interfere with the phase difference of \(φ\) is given by
In LCR series circuit at resonance
The resistor '\(R\)' inductance '\(L\)' and capacitance '\(C\)' are connected in series with an a.c. source. When 'L' is removed from the circuit, the phase difference between voltage and current in the circuit is \(\frac{π}{3}\). If instead, C is removed from the circuit, the phase difference is again \(\frac{π}{3}\). The power factor of the circuit is