In a Young’s double slit experiment the ratio of the slit’s width is \(4 : 1.\) The ratio of the intensity of maxima to minima, close to central fringe on the screen will be

Two light beams fall on a transparent material block at point 1 and 2 with angle \(\theta_1\) and \(\theta_{2^{\prime}}\) respectively, as shown in figure. After refraction, the beams intersect at point 3 which is exactly on the interface at other end of the block. Given : the distance between 1 and 2, \(\mathrm{d}=4 \sqrt{3} \mathrm{~cm}\) and \(\theta_1=\theta_2=\cos ^{-1}\left(\frac{\mathrm{n}_2}{2 \mathrm{n}_1}\right)\), where refractive index of the block \(\mathrm{n}_2\gt\) refractive index of the outside medium \(\mathrm{n}_1\), then the thickness of the block is ________ cm.

A parallel plate capacitor has plate area \(40\,cm ^2\) and plates separation \(2\,mm\). The space between the plates is filled with a dielectric medium of a thickness \(1\,mm\) and dielectric constant \(5\) . The capacitance of the system is :

A paralle plate capacitor is made up of stair like structure with a palte area \(A\) of each stair and that is connected with a wire of length \(b\), as shown in the figure. The capacitance of the arrangement is \(\frac{ x }{15} \frac{\varepsilon_{0} A }{ b }\). The value of \(x\) is ............

An ideal gas enclosed in a vertical cylindrical container supports a freely moving piston of mass \(M\). The piston and the cylinder have equal cross sectional area \(A\). When the piston is in equilibrium, the volume of the gas is \(V_0\) and its pressure is \(P_ 0\). The piston is slightly displaced from the equilibrium position and released. Assuming that the system is completely isolated from its surrounding, the piston executes a simple harmonic motion with frequency

A fighter plane of length \(20\, m\), wing span (distance from tip of one wing to the tip of the other wing) of \(15\,m\) and height \(5\,m\) is lying towards east over Delhi. Its speed is \(240\, ms^{-1}\) . The earth's magnetic field over Delhi is \(5 \times 10^{-5}\,T\) with the declination angle \( \sim {0^o}\) and dip of \(\theta\) such that \(\sin \,\theta  = \frac{2}{3}\). If the voltage developed is \(V_B\) between the lower and upper side of the plane and \(V_W\) between the tips of the wings then \(V_B\) and \(V_W\) are close to

A Carnot freezer takes heat from water at \(0\,^oC\) inside it and rejects it to the room at a temperature of \(27\,^oC\). The latent heat of ice is \(336 \times 10^3\, J\,kg^{-1}\).  lf \(5\, kg\) of water at \(0\,^oC\) is converted into ice at  \(0\,^oC\) by the freezer, then the energy consumed by the freezer is close to

The surface tension of soap solution is \(3.5 \times 10^{-2}\,Nm ^{-1}\). The amount of work done required to increase the radius of soap bubble from \(10\,cm\) to \(20\,cm\) is \(.....\times 10^{-4}\,J\)

Consider a mixture of gas molecule of types \(A, B\) and \(C\) having masses \(m_{A}\,<\,m_{B}\,<\,m_{C}\) ratio of their root mean square speeds at normal temperature and pressure is :

A liquid drop having \(6\) excess electrons is kept stationary under a uniform electric field of \(25.5\, k\,Vm^{-1}\) . The density of liquid is \(1.26\times10^3\, kg\, m^{-3}\) . The radius of the drop is (neglect buoyancy)

Two polarisers \(P_1\) and \(P_2\) are placed in such a way that the intensity of the transmitted light will be zero. A third polariser \(P_3\) is inserted in between \(P_1\) and \(\mathrm{P}_2\), at the particular angle between \(\mathrm{P}_2\) and \(\mathrm{P}_3\). The transmitted intensity of the light passing the through all three polarisers is maximum. The angle between the polarisers \(\mathrm{P}_2\) and \(\mathrm{P}_3\) is :

A string \(2.0\, m\) long and fixed at its end is driven by a \(240\, Hz\) vibrator. The string vibrates in its third harmonic mode. The speed of the wave and its fundamental frequency is

A player caught a cricket ball of mass \(150 \mathrm{~g}\) moving at a speed of \(20 \mathrm{~m} / \mathrm{s}\). If the catching process is completed in \(0.1 \mathrm{~s}\), the magnitude of force exerted by the ball on the hand of the player is _______.