A plane electromagnetic wave of frequency 20 MHz travels in free space along the \(+x\) direction. At a particular point in space and time, the electric field vector of the wave is \(\mathrm{E}_y=9.3 \mathrm{Vm}^{-1}\). Then, the magnetic field vector of the wave at that point is:

The equations of two waves are given by \(y_{1}=5 \sin 2 \pi(x-v t) \,c m\,\) \(y_{2}=3 \sin 2 \pi(x-v t+1.5) \,c m\) These waves are simultaneously passing through a string. The amplitude of the resulting wave is.........\(cm\)

Following statements are given : \((1)\) The average kinetic energy of a gas molecule decreases when the temperature is reduced. \((2)\) The average kinetic energy of a gas molecule increases with increase in pressure at constant temperature. \((3)\) The average kinetic energy of a gas molecule decreases with increases in volume. \((4)\) Pressure of a gas increases with increase in temperature at constant pressure. \((5)\) The volume of gas decreases with increase in temperature. Choose the correct answer from the options given below:

The width of fringe is \(2\,mm\) on the screen in a double slits experiment for the light of wavelength of \(400\,nm\). The width of the fringe for the light of wavelength \(600\,nm\) will be \(..............\,mm\)

The work function of a metal is 3 eV. The color of the visible light that is required to cause emission of photoelectrons is _______.

A bi convex lens of focal length \(10\,cm\) is cut in two identical parts along a plane perpendicular to the principal axis. The power of each lens after cut is \(...........\,D\).

Angular momentum of an electron in a hydrogen atom is \(\dfrac{3h}{\pi}\), then the energy of the electron is _______ eV.

A galvanometer is used in laboratory for the null point in electrical experiments. If, on passing a current of \(6 \,m A\) it produces a deflection of \(2^{\circ},\) its figure of merit is close to :

In an experiment a sphere of aluminium of mass \(0.20\, kg\) is heated upto \(150\,^oC\). Immediately, it is put into water of volume \(150\, cc\) at \(27\,^oC\) kept in a calorimeter of water equivalent to \(0.025\, kg\). Final temperature of the system is \(40\,^oC\). The specific heat of aluminium is ............ \(J/kg\,-\,^oC\) (take \(4.2\, Joule= 1\, calorie\))

The internal energy of air in \(4 \mathrm{~m} \times 4 \mathrm{~m} \times 3 \mathrm{~m}\) sized room at 1 atmospheric pressure will be _______ \(\times 10^6 \mathrm{~J}\). (Consider air as diatomic molecule)

Two point charges \(Q\) each are placed at a distance \(d\) apart. A third point charge \(q\) is placed at a distance \(x\) from mid-point on the perpendicular bisector. The value of \(x\) at which charge \(q\) will experience the maximum \(Coulomb's force\) is ...............

The ratio of mass densities of nuclei of \(^{40}Ca\) and \(^{16}O\) is close to