Question
Classify metals, conductors and semiconductors.
✓
Answer
On the basis of conductivity : On the basis of relative value of electrical conductivity ( $\sigma$ ) or resistivity ( $\rho=$ $1 / \sigma$ ) solid materials are classified as follows :
(i) Metals: Their resistivity is very low (or conductivity is very high).
$\begin{array}{l}
\rho \sim 10^{-2}-10^{-8} \Omega m \\
\sigma \sim 10^2-10^8 Sm^{-1}
\end{array}$
(ii) Semiconductors : Their resistivity or conductivity is between metals and insulating materials.
$\begin{array}{l}
\rho \sim 10^{-5}-10^6 \Omega m \\
\sigma \sim 10^5-10^{-6} Sm^{-1}
\end{array}$
(iii) Insulators : Their resistance is very high (or conductivity is very low).
$\begin{array}{l}
\rho \sim 10^{11}-10^{19} \Omega m \\
\sigma \sim 10^{-11}-10^{-19} Sm^{-1}
\end{array}$
The values of $\rho$ and $\sigma$ given above are only indicative of the order value and may go outside the given range.
(i) Metals: Their resistivity is very low (or conductivity is very high).
$\begin{array}{l}
\rho \sim 10^{-2}-10^{-8} \Omega m \\
\sigma \sim 10^2-10^8 Sm^{-1}
\end{array}$
(ii) Semiconductors : Their resistivity or conductivity is between metals and insulating materials.
$\begin{array}{l}
\rho \sim 10^{-5}-10^6 \Omega m \\
\sigma \sim 10^5-10^{-6} Sm^{-1}
\end{array}$
(iii) Insulators : Their resistance is very high (or conductivity is very low).
$\begin{array}{l}
\rho \sim 10^{11}-10^{19} \Omega m \\
\sigma \sim 10^{-11}-10^{-19} Sm^{-1}
\end{array}$
The values of $\rho$ and $\sigma$ given above are only indicative of the order value and may go outside the given range.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
More "3 Marks Question" from Semiconductor Electronics: Materials, Devices and Simple Circuits→Semiconductor Electronics: Materials, Devices and Simple Circuits — all question types→Physics STD 12 Science question papers→Gujarat Board STD 12 Science question papers→Gujarat Board question paper generator→
Similar questions
A short bar magnet of magnetic moment 5.25 × 10–2J T–1 is placed with its axis perpendicular to the earth’s field direction. At what distance from the centre of the magnet, the resultant field is inclined at 45° with earth’s field on (a) its normal bisector and (b) its axis. Magnitude of the earth’s field at the place is given to be 0.42 G. Ignore the length of the magnet in comparison to the distances involved.
- In a typical nuclear reaction, e.g.
$^{2}_{1}\text{H} +^{2}_{1}\text{H}\rightarrow^{3}_{2}\text{He} + \text{n} + 3.27\text{MeV}$
although number of nucleons is conserved, yet energy is released. How? Explain.
- Show that nuclear density in a given nucleus is independent of mass number A.
How many time constants will elapse before the power delivered by a battery drops to half of its maximum value in an RC circuit?
A small piece of wood is floating on the surface of a 2.5m deep lake. Where does the shadow form on the bottom when the sun is just setting? Refractive index of water $=\frac{4}{3}.$
→(a) Calculate the potential at a point P due to a charge of $4 \times 10^{-7} C$ located 9 cm away.
(b) Hence obtain the work done in bringing a charge of $2 \times 10^{-9} C$ from infinity to the point $P$. Does the answer depend on the path along which the charges is brought?
→(b) Hence obtain the work done in bringing a charge of $2 \times 10^{-9} C$ from infinity to the point $P$. Does the answer depend on the path along which the charges is brought?
Explain the series connection of capacitors.
A circular coil of 200 turns and radius 10 cm is placed in a uniform magnetic field of 0.5 T, normal to the plane of the coil. If the current in the coil is 3.0 A, calculate the
- Total torque on the coil.
- Total force on the coil.
- Average force on each electron in the coil, due to the magnetic field.
The geostationary orbit of the earth is at a distance of about 36000km from the earth's surface. Find the weight of a 120kg equipment placed in a geostationary satellite. The radius of the earth is 6400km.
A battery of $10 V$ and negligible internal resistance is connected across the diagonally opposite corners of a cubical network consisting of 12 resistors each of resistance $1 \Omega$ (Fig. 3.16). Determine the equivalent resistance of the network and the current along each edge of the cube.
→5g of a gas is contained in a rigid container and is heated from 15°C to 25°C. Specific heat capacity of the gas at constant volume is 0.172cal-g-1°C-1 and the mechanical equivalent of heat is 4.2J-cal-1. Calculate the change in the internal energy of the gas.