Two point charges \(A\) and \(B\) of magnitude \(+8 \times 10^{-6}\,C\) and \(-8 \times 10^{-6}\,C\) respectively are placed at a distance \(d\) apart. The electric field at the middle point \(O\) between the charges is \(6.4 \times 10^{4}\,NC ^{-1}\). The distance ' \(d\) ' between the point charges \(A\) and \(B\) is..............\(m\)

A steel wire with mass per unit length \(7.0 \times 10^{-3}\,kg\,m ^{-1}\) is under tension of \(70\,N\). The speed of transverse waves in the wire will be \(.........m/s\)

\(27\) similar drops of mercury are maintained at \(10 \,V\) each. All these spherical drops combine into a single big drop. The potential energy of the bigger drop is ....... times that of a smaller drop.

A closely wounded circular coil of radius \(5\,cm\) produces a magnetic field of \(37.68 \times 10^{-4}\,T\) at its center. The current through the coil is \(......A\). [Given, number of turns in the coil is \(100\) and \(\pi=3.14]\)

In the circuit shown, the energy stored in the capacitor is \(n\,\mu J\). The value of \(n\) is ..............

The figure shows a region of length \('l'\) with a uniform magnetic field of \(0.3\, T\) in it and a proton entering the region with velocity \(4 \times 10^{5}\, ms ^{-1}\) making an angle \(60^{\circ}\) with the field. If the proton completes \(10\) revolution by the time it cross the region shown, \(l\) is close to....... \(m\) (mass of proton \(=1.67 \times 10^{-27} \,kg ,\) charge of the proton \(\left.=1.6 \times 10^{-19}\, C \right)\)

A particle starts with an initial velocity of \(10.0\,ms ^{-1}\) along \(x\)-direction and accelerates uniformly at the rate of \(2.0\,ms ^{-2}\). The time taken by the particle to reach the velocity of \(60.0\,ms ^{-1}\) is \(.......\,s\)

Which level of the single ionized carbon has the same energy as the ground state energy of hydrogen atom ?