A galvanometer coil has \(500\) turns and each turn has an average area of \(3 \times 10^{-4}\, m ^{2}\). If a torque of \(1.5\,Nm\) is required to keep this coil parallel to magnetic field when a current of \(0.5\, A\) is flowing through it, the strength of the field (in \(T )\) is

The source of time varying magnetic field may be \((A)\) a permanent magnet \((B)\) an electric field changing linearly with time \((C)\) direct current \((D)\) a decelerating charge particle \((E)\) an antenna fed with a digital signal Choose the correct answer from the options given below:

In a coil, the current changes form \(-2 \mathrm{~A}\) to \(+2 \mathrm{~A}\) in \(0.2 \mathrm{~s}\) and induces an emf of \(0.1 \mathrm{~V}\). The selfinductance of the coil is _______.

Which of the four resistances \(P, Q, R\) and \(S\) generate the greatest amount of heat when a current flows from \(A\) to \(B\) ?

\(\begin{array}{c|c|c} A & B & Y \\\hline 0 & 0 & 1 \\0 & 1 & 1 \\1 & 0 & 0 \\1 & 1 & 1\end{array}\)
To obtain the given truth table, following logic gate should be placed at G :

A small bob of mass 100 mg and charge \(+10 \mu \mathrm{C}\) is connected to an insulating string of length 1 m. It is brought near to an infinitely long nonconducting sheet of charge density ' \(\sigma\) ' as shown in figure. If string subtends an angle of \(45^{\circ}\) with the sheet at equilibrium the charge density of sheet will be :
(Given, \(\varepsilon_0=8.85 \times 10^{-12} \frac{\mathrm{~F}}{\mathrm{~m}}\) and acceleration due to gravity, \(g=10 \mathrm{~m} / \mathrm{s}^2\))

An object is projected in the air with initial velocity \(u\) at an angle \(\theta\). The projectile motion is such that the horizontal range \(R\), is maximum. Another object is projected in the air with a horizontal range half of the range of first object. The initial velocity remains same in both the case. The value of the angle of projection, at which the second object is projected, will be \(.......\) degree.

A point source of \(100\,W\) emits light with \(5 \%\) efficiency. At a distance of \(5\,m\) from the source, the intensity produced by the electric field component is :

Hydrogen \((_1H^1),\) Deuterium \((_1H^2)\),singly ionised Helium \((_2He^4)^+\) and doubly ionised lithium \({\left( {{}_3^6Li} \right)^{ + + }}\), all have one electron around the nucleus. Consider an electron transition from \(n = 2\) to \(n = 1\). If the wavelengths of emitted radiation are \(λ_1,λ_2,λ_3\) and \(λ_4\) respectively then approximately which one of the following is correct?

An object is located at \(2\, km\) beneath the surface of the water. If the fractional compression \(\frac{\Delta V }{ V }\) is \(1.36\, \%,\) the ratio of hydraulic stress to the corresponding hydraulic strain will be ......... . [Given : density of water is \(1000\, kg m ^{-3}\) and \(\left. g =9.8 \,ms ^{-2} .\right]\)