Physics

A long solenoid of radius $R$ $$ carries a time ( $t)$ $$ dependent current ${}_{}$ $I\left(t\right)=I_{0}t(1-t)$ . A ring of radius $2R$ $$ is placed cordially near its middle. During the time internal $0\le t\le 1$ $$ , the induced current $\left(I_R\right)$ $\left({}_{}\right)$ and the induced $\mathrm{E}\mathrm{M}\mathrm{F}?\left(V_R\right)$ $\left({}_{}\right)$ in the ring changes as:

In finding the electric field using Gauss law the formula $\left|\stackrel{?}{E}\right|=\frac{q_{\text{enc}}}{{\epsilon }_0\left|A\right|}$ $\stackrel{}{}\frac{{}_{}}{{}_{}}$ is applicable. In the formula ${\epsilon }_0$ ${}_{}$ is permittivity of free space, $A$ $$ is the area of Gaussain surface and $q_{\text{enc}}$ ${}_{}$ is charge enclosed by the Gaussian surface. This equation can be used in which of the following situation? Only when the Gaussian surface is an

In a Young's double slit experiment, the separation between the slits is $0.15\mathrm{m}\mathrm{m}$ . In the experiment, a source of light of wavelength $589\mathrm{n}\mathrm{m}$ is used and the interference pattern is observed on a screen kept $1.5\mathrm{m}$  away. The separation between the successive bright fringes on the screen is:

When photon of energy $4.0\mathrm{e}\mathrm{V}$ $$ strikes the surface of a metal $A$ $$ , the ejected photoelectrons have maximum kinetic energy $T_A$ ${}_{}$ eV and de-Broglie wavelength ${\lambda }_A$ ${}_{}$ . The maximum kinetic energy of photoelectrons liberated form another metal B by photon of energy 4.50 $\mathrm{e}\mathrm{V}$ $$ is $T_B=\left(T_A-1.5\right)eV$ ${}_{}\left({}_{}\right)$ . If the de-Broglie wavelength of these photoelectrons ${\lambda }_B=2{\lambda }_A$ ${}_{}{}_{}$ , then the work function of metal $$ $B$ is

Two infinite planes each with uniform surface charge density $+\sigma$ $$ are kept in such a way that the angle between them is ${30}^{?}$ ${}^{}$ . The electric field in the region shown between them is given by:

The dimension of $\frac{{\mathrm{B}}^2}{2{\mu }_0}$ , where $\mathrm{B}$ is magnetic field and ${\mu }_0$  is the magnetic permeability of vacuum, is

A polarizer-analyser set is adjusted such that the intensity of light coming out of the analyser is just $10\mathrm{\%}$ $$ of the original intensity. Assuming that the polarizer-analyser set does not absorb any light, the angle by which the analyser need to be rotated further to reduce the output intensity to be zero is

The coordinates of centre of mass of a uniform flag shaped lamina (thin flat plate) of mass 4 $\mathrm{k}\mathrm{g}$ . (the coordinates of the same are shown in figure) are:

A box weighs $196\mathrm{N}$ on a spring balance at the north pole. Its weight recorded on the same balance if it is shifted to the equator is close to (Take $\mathrm{g}=10{\mathrm{m}\mathrm{s}}^{-2}$ at the north pole and the radius of the earth $=6400\mathrm{k}\mathrm{m}$  )

A thermodynamic cycle $xyzx$ is shown on a $V-T$  diagram. The P-V diagram that best describes this cycle is: (diagrams are schematic and not to scale)