In a fluorescent lamp choke (a small transformer) \(100 \;\mathrm{V}\) of reverse voltage is produced when the choke current changes uniformly from \(0.25 \;\mathrm{A}\) to \(0\;\mathrm{A}\) in a duration of \(0.025 \;\mathrm{ms} .\) The self-inductance of the choke (in \(\mathrm{mH})\) is estimated to be

An electron, a doubly ionized helium ion \(\left( He ^{++}\right)\) and a proton are having the same kinetic energy. The relation between their respective de\(-\)Broglie wavelengths \(\lambda_{ e }, \lambda_{ He ^{++}}\) and \(\lambda_{ P }\) is

The angle of projection for a projectile to have same horizontal range and maximum height is _______.

As shown in figure, a \(70\,kg\) garden roller is pushed with a force of \(\overrightarrow{ F }=200\,N\) at an angle of \(30^{\circ}\) with horizontal. The normal reaction on the roller is \(.......\,N\) \(\left(\right.\) Given \(\left.g =10\,m s ^{-2}\right)\)

A sinusoidal voltage of peak value \(283\, V\) and angular frequency \(320/s\) is applied to a series \(LCR\) circuit. Given that \(R\, = 5\,\Omega \) , \(L\,= 25\, mH\) and \(C\, = 1000\, \mu F\). The total impedance, and phase difference between the voltage across the source and the current will respectively be

In the figure shown \(ABC\) is a uniform wire . If centre of mass of wire lies vertically below point \(A\) , then \(\frac{{BC}}{{AB}}\) is close to 

In a Young's double slit experiment, the intensities at two points, for the path difference \(\frac{\lambda}{4}\) and \(\frac{\lambda}{3}\) ( \(\lambda\) being the wavelength of light used) are \(I_1\) and \(I_2\) respectively. If \(I_0\) denotes the intensity produced by each one of the individual slits, then \(\frac{ I _1+ I _2}{ I _0}=..............\)

The equivalent capacitance between \(A\) and \(B\) in the circuit given below is.....\(μF\)

Two short electric dipoles \(A\) and \(B\) having dipole moment \(p_1\) and \(p_2\) respectively are placed with their axis mutually perpendicular as shown in the figure. The resultant electric field at a point \(x\) is making an angle of \(60°\) with the line joining points \(O\) and \(x\). The ratio of the dipole moments \(p_2/p_1\) is _______.

Consider a uniform wire of mass \(M\) and length \(L\). It is bent into a semicircle. Its moment of inertia about a line perpendicular to the plane of the wire passing through the centre is :

A proton, an electron and an alpha particle have the same energies. Their de-Broglie wavelengths will be compared as _______.

Three masses \(M =100\,kg , m _{1}=10\,kg\) and \(m_{2}=20\,kg\) are arranged in a system as shown in figure. All the surfaces are frictionless and strings are inextensible and weightless. The pulleys are also weightless and frictionless. \(A\) force \(F\) is applied on the system so that the mass \(m_{2}\) moves upward with an acceleration of \(2\,ms ^{-2}\). The value of \(F\) is \(......N\) \(\left(\right.\) Take \(\left.g =10\,ms ^{-2}\right)\)