The rms value of the electric field of an electromagnetic wave emitted by a source is \(660 \mathrm{NC}^{-1}\). The average energy density of the electromagnetic wave is

If $f^{\text{'}}\left(x\right)=a\sin x+b\cos x, f^{\text{'}}\left(0\right)=4, f\left(0\right)=3$ and $f\left(\frac{\mathrm{\pi }}{2}\right)=5,$ then $f\left(x\right)=$

Charge 'Q' (in coulomb) flowing through a conductor in terms of time 't' (in second) is given by the equation \(Q=3 t^2+t\). The current in the conductor at time \(\mathrm{t}=3 \mathrm{~s}\) is

When a light of wavelength \(4900 Å\) falls on a photosensitive metal, a negative \(2 \mathrm{~V}\) potential is required to stop the emitted electrons. Then, the work-function of the material is nearly
( given charge on electron \(=1.602 \times 10^{-19} \mathrm{C}\) and Planck's constant \(=6.625 \times 10^{-34} \mathrm{Js}\) )

In the figure shown, \(\mathrm{AB}\) is a rod of length \(30 \mathrm{~cm}\), area of cross-section \(1 \mathrm{~cm}^2\) and thermal conductivity \(336 \mathrm{SI}\) units. The ends \(\mathrm{A}\) and \(\mathrm{B}\) are at constant temperatures \(20^{\circ} \mathrm{C}\) and \(40^{\circ} \mathrm{C}\) respectively. A point \(\mathrm{C}\) of the rod is connected to ice at \(0^{\circ} \mathrm{C}\) in a thermally insulated box \(\mathrm{D}\) through a highly conducting wire of negligible heat capacity. The rate at which ice melts in the box is \(\left(\mathrm{L}_{\mathrm{ice}}=80 \mathrm{cal} \mathrm{g}^{-1}\right)\)

Two waves are represented by: $x_1=A\sin \left(\omega t+\frac{\pi }{6}\right)$ and $x_2=A\cos \omega t$. Then the phase difference between them is

The distance covered by a stone dropped from the top of a building in the last second of its motion is 0.36 times the total distance travelled by it. The height of the building is (acceleration due to gravity \(=9.8 \mathrm{~ms}^{-2}\) )

What are the products formed when moist chlorine gas is reacted with hypo?

117.An L-C resonant circuit contains a 400 pF capacitor and an inductor of 400 μH. It is coupled to an antenna. Wavelength of
radiated electromagnetic wave is

The volume of a spherical ball is increasing at a rate of \(4 \pi \mathrm{cm}^3 \mathrm{~s}^{-1}\). The rate at which its radius increases, when its volume is \(288 \pi \mathrm{cm}^3\), is.......\(\mathrm{cm} \mathrm{s}^{-1}\)

A body is travelling with \(10 \mathrm{~ms}^{-1}\) on a rough horizontal surface. It's velocity after \(2 \mathrm{~s}\) is \(4 \mathrm{~ms}^{-1}\). The coefficient of kinetic friction between the block and the plane is
(acceleration due to gravity \(=10 \mathrm{~ms}^{-2}\) )

Calculate \(\Delta H\) in \(\mathrm{kJ}\) for the following reaction
\[
\mathrm{C}(\mathrm{g})+\mathrm{O}_2(\mathrm{~g}) \longrightarrow \mathrm{CO}_2(\mathrm{~g})
\]
Given that,
\[
\begin{gathered}
\mathrm{H}_2 \mathrm{O}(g)+\mathrm{C}(g) \longrightarrow \mathrm{CO}(g)+\mathrm{H}_2(g) ; \\
\Delta H=+131 \mathrm{~kJ} \\
\mathrm{CO}(g)+\frac{1}{2} \mathrm{O}_2(g) \longrightarrow \mathrm{CO}_2(g) ; \\
\Delta H=-282 \mathrm{~kJ} \\
\mathrm{H}_2(g)+\frac{1}{2} \mathrm{O}_2(g) \longrightarrow \mathrm{H}_2 \mathrm{O}(g) ; \\
\Delta H=-242 \mathrm{~kJ}
\end{gathered}
\]

The number of electric lines that emerge from a finite charge $+q$ is _____