JEE Main 2003 — Modern Physics

The difference in the variation of resistance with temperature in a metal and a semiconductor arises essentially due to the difference in the

Two identical photocathodes receive light of frequencies $\mathrm{f}_1$ and $\mathrm{f}_2$. If the velocities of the photo electrons (of mass $\mathrm{m}$ ) coming out are respectively $\mathrm{v}_1$ and $\mathrm{v}_2$, then

In the middle of the depletion layer of a reverse biased p-n junction, the

If the binding energy of the electron in a hydrogen atom is $13.6 \mathrm{eV}$, the energy required to remove the electron from the first excited state of $\mathrm{Li}^{++}$is

Which of the following atoms has the lowest ionization potential?

The wavelengths involved in the spectrum of deuterium $\left({ }_1^2 \mathrm{D}\right)$ are slightly different from that of hydrogen spectrum, because

When a $U^{238}$ nucleus originally at rest, decays by emitting an alpha particle having a speed ' $u$ ', the recoil speed of the residual nucleus is

A nucleus with $\mathrm{Z}=92$ emits the following in a sequence: $\alpha, \beta^{-}, \beta^{-} \alpha, \alpha, \alpha, \alpha, \alpha, \beta^{-}, \beta^{-}, \alpha, \beta^{+}, \beta^{+}, \alpha$. Then $\mathrm{Z}$ of the resulting nucleus is