Exercise - 3

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

The electrical conductivity of a semiconductor increases when electromagnetic radiation of wavelength shorter than $2480 \mathrm{nm}$ is incident on it. The band gap, in ($\mathrm{eV}$), for the semiconductor is,

In a common base amplifier, the phase difference between the input signal voltage and output voltage is,

In a full-wave rectifier circuit operating from $50 \mathrm{Hz}$ mains frequency, the fundamental frequency in the ripple would be

If the ratio of the concentration of electrons to that of holes in a semiconductor is $\frac{7}{5}$ and the ratio of currents is $\frac{7}{4}$, then what is the ratio of their drift velocity?

Carbon, silicon and germanium have four valence electrons each. At room temperature, which one of following statements is most appropriate?

A working transistor with its three legs marked $P\text{,} Q$ and $R$ is tested using a multimeter. No conduction is found between $P$ and $Q$. By connecting the common (negative) terminal of the multimeter to $R$ and the other (positive) terminal to $P$ and $Q$, some resistance is seen on the multimeter. Which of the following is true for the transistor?

The output of an $\mathrm{OR}$ gate is connected to both the inputs of a $\mathrm{NAND}$ gate. The combination will serve as a