A photon and an electron have an equal energy ' E '. The ratio of wavelength ' $\lambda_{\mathrm{p}}$ ' of photon to that of electron ' $\lambda_{\mathrm{e}}$ ' is proportional to
The height at which the acceleration due to gravity becomes $\frac{g}{4}$ in terms of $R$ is $[R=$ the radius of the earth $]$
In a biprism experiment, fifth dark fringe is obtained at a point. A thin transparent film of refractive index ' $\mu$ ' is placed in one of the interfering paths. Now $7^{\text {th }}$ bright fringe is obtained at the same point. If ' $\lambda$ ' is the wavelength of light used, the thickness of film is equal to
Figure shows a rectangular frame situated in a constant magnetic field. A wire BC of length 1 m is moved out with velocity $4 \mathrm{~m} / \mathrm{s}$. Magnetic field strength is 0.15 T . Force acting on the wire $B C$ is
