If a source of electromagnetic radiation having power \(15 kW\) produces \(10^{16}\) photons per second, the radiation belongs to a part of spectrum is.(Take Planck constant \(h =6 \times 10^{-34}\,Js\) )

A body of mass 2 kg is moving along x -direction such that its displacement as function of time is given by \(x ( t )=\alpha t ^2+\beta t +\gamma m\), where \(\alpha=1 m / s ^2\), \(\beta=1 m / s\) and \(\gamma=1 m\). The work done on the body during the time interval \(t =2 s\) to \(t =3 s\), is _________ J.

A \(0.5 \,kg\) block moving at a speed of \(12 \,ms ^{-1}\) compresses a spring through a distance \(30\, cm\) when its speed is halved. The spring constant of the spring will be \(Nm ^{-1}\).

A conducting circular loop made of a thin wire, has area \(3.5 \times 10^{-3}\, m^2\) and resistance \(10\,\Omega \). It is placed perpendicular to a time dependent magnetic field \(B(t) = (0.4\,T)\, sin\, (50\, \pi t)\). The field is uniform in space. Then the net charge flowing through the loop during \(t = 0\, s\) and \(t = 10\, ms\) is close to.......\(mC\)

An electron is allowed to move with constant velocity along the axis of current carrying straight solenoid. \(A.\) The electron will experience magnetic force along the axis of the solenoid. \(B.\) The electron will not experience magnetic force. \(C.\) The electron will continue to move along the axis of the solenoid. \(D.\) The electron will be accelerated along the axis of the solenoid. \(E.\) The electron will follow parabolic path-inside the solenoid. Choose the correct answer from the options given below:

Your friend is having eye sight problem. She is not able lo see clearly a distant uniform window mesh and it appears to her as non-uniform and distorted. The doctor diagnosed the problem as

A smooth inclined plane ends in a vertical circular loop, as shown in the figure. A small body is released from height \(h\) as shown. If the body exerts a force of three times its weight on the plane at the highest point of circle then the height \(h = \alpha R\). The value of \(\alpha\) is _______.

A coil is placed in magnetic field such that plane of coil is perpendicular to the direction of magnetic field. The magnetic flux through a coil can be changed: \(A.\) By changing the magnitude of the magnetic field within the coil. \(B.\) By changing the area of coil within the magnetic field. \(C.\) By changing the angle between the direction of magnetic field and the plane of the coil. \(D.\) By reversing the magnetic field direction abruptly without changing its magnitude. Choose the most appropriate answer from the options given below

A bi-convex lens has radius of curvature of both the surfaces same as \(1 / 6 \mathrm{~cm}\). If this lens is required to be replaced by another convex lens having different radii of curvatures on both sides \(\left(R_1 \neq R_2\right)\), without any change in lens power then possible combination of \(R_1\) and \(R_2\) is :

In the circuit shown in the figure, the ratio of the quality factor and the band width is \(.............\) s.