Physics Test - ...

An infinite line charge produces a field of \(9 \times 10^{4} \mathrm{~N} / \mathrm{C}\) at a distance of \(2 \mathrm{~cm} .\) Calculate the linear charge density.

If the bio-convex lens is cut as shown in the figure, the new focal length \(f^{\prime}\) is:

Two-point charges \(+8q\) and \(-2q\) are located at \(x = 0\) and \(x = L\) respectively. The location of a point on the \(X\)-axis at which the net electric field due to these two point charges is zero is:

The SI unit of refractive index is ____________

In the circuit shown the value of \(\mathscr{I}\) in ampere is:

Gauss's law for magnetism states that, the net _______ through any closed surface is zero.

Two identical photocathodes receive light of frequencies \({f}_{1}\) and \({f}_{2}\). If the velocities of the photoelectrons (ofmass \({m}\) ) coming out are \({v}_{1}\) and \({v}_{2}\), respectively, then:

The image formed by a concave spherical mirror:

Two satellites of masses \(3 \mathrm{M}\) and \(\mathrm{M}\) orbit the earth in the circular orbits of radii \(\mathrm{r}\) and \(3 \mathrm{r}\) respectively. The ratio of their orbital velocities is:

In the given circuit, charge \(\mathrm{Q}_{2}\) on the \(2 \mu \mathrm{F}\) capacitor changes as \(\mathrm{C}\) is varied from \(1 \mu \mathrm{F}\) to \(3 \mu \mathrm{F} . \mathrm{Q}_{2}\) as a function of \(\mathrm{C}\) is given properly by: