Exercise

Identify the process in which an electron escapes from the metal surface.

Which of the following equation is wrong?(symbols have their usual meaning)

Three photo diodes $D1, D2$ and $D3$ are made of semiconductors having band gaps of $2.5\mathrm{eV}, 2\mathrm{eV}$ and $3\mathrm{eV}$, respectively. Which ones will be able to detect light of wavelength $600 nm$ ?

Given Planck constant is $h=6.62\times {10}^{-34} m^2 kg s^{-1}$,speed of light $c=3\times {10}^{8 }m{s}^{-1}$

What are the applications of medical physics?

Depict the magnetic field lines due to two straight long parallel conductors carrying currents ${\mathrm{I}}_1$ and ${\mathrm{I}}_2$ in the same direction. Hence, deduce an expression for the force acting per unit length on one conductor due to the other. Is this force attractive or repulsive? Hence, define one ampere.

What is the principle of RADAR? Write the applications of RADAR.

An $\alpha$-particle and a proton are accelerated from rest by a potential difference of $100 \mathrm{V}$.  After this, their De-Broglie wavelength are ${\mathrm{\lambda }}_{\mathrm{\alpha }}$ and ${\mathrm{\lambda }}_{\mathrm{p}}$ respectively. The ratio $\frac{{\lambda }_p}{{\lambda }_{\alpha }}$ to the nearest is

Why does a $p-n$ junction diode offer low resistance in forward bias and a high resistance in reverse bias? Explain the characteristic curve of a diode by drawing suitable circuit diagram.