Q. No.In the energy band diagram of a material shown below, the open circles and filled circles denote holes and electrons respectively. The material is a/an:
| 1. | \(\mathrm{p}\text-\)type semiconductor |
| 2. | insulator |
| 3. | metal |
| 4. | \(\mathrm{n}\text-\)type semiconductor |
To unlock all the explanations of this course, you need to be enrolled.
To unlock all the explanations of this course, you need to be enrolled.
In a good conductor, the energy gap between the conduction band and the valence band is:
1. Infinite
2. Wide
3. Narrow
4. Zero
To unlock all the explanations of this course, you need to be enrolled.
To unlock all the explanations of this course, you need to be enrolled.
| 1. | The resistivity of a semiconductor increases with an increase in temperature. |
| 2. | Substances with an energy gap of the order of \(10\) eV are insulators. |
| 3. | In conductors, the valence and conduction bands may overlap. |
| 4. | The conductivity of a semiconductor increases with an increase in temperature. |
To unlock all the explanations of this course, you need to be enrolled.
To unlock all the explanations of this course, you need to be enrolled.
Carbon, Silicon, and Germanium atoms have four valence electrons each. Their valence and conduction bands are separated by energy gaps represented by \(\left(E_g\right)_C,(E_g)_{Si}~\text{and}~(E_g)_{Ge}\) respectively. Which one of the following relationships is true in their case?
| 1. | \(\left(E_g\right)_C<\left(E_g\right)_{G e} \) | 2. | \(\left(E_g\right)_C>\left(E_g\right)_{S i} \) |
| 3. | \(\left(E_g\right)_C=\left(E_g\right)_{S i} \) | 4. | \(\left(E_g\right)_C<\left(E_g\right)_{S i}\) |
To unlock all the explanations of this course, you need to be enrolled.
To unlock all the explanations of this course, you need to be enrolled.
The energy band diagrams for semiconductor samples of silicon are as shown. We can assert that:
| 1. | Sample \(X\) is undoped while samples \(Y\) and \(Z\) have been doped with a third group and a fifth group impurity respectively. |
| 2. | Sample \(X\) is undoped while both samples \(Y\) and \(Z\) have been doped with a fifth group impurity. |
| 3. | Sample \(X\) has been doped with equal amounts of third and fifth group impurities while samples \(Y\) and \(Z\) are undoped. |
| 4. | Sample \(X\) is undoped while samples \(Y\) and \(Z\) have been doped with a fifth group and a third group impurity respectively. |
To unlock all the explanations of this course, you need to be enrolled.
To unlock all the explanations of this course, you need to be enrolled.
In semiconductors at room temperature:
| 1. | The valence band is completely filled and the conduction band is partially filled. |
| 2. | The valence band is completely filled. |
| 3. | The conduction band is completely empty. |
| 4. | The valence band is partially empty and the conduction band is partially filled. |
To unlock all the explanations of this course, you need to be enrolled.
To unlock all the explanations of this course, you need to be enrolled.
1. \(6000~\mathring{A}\)
2. \(4000\) nm
3. \(6000\) nm
4. \(4000~\mathring{A}\)
To unlock all the explanations of this course, you need to be enrolled.
To unlock all the explanations of this course, you need to be enrolled.
How much is the forbidden gap (approximately) in the energy bands of germanium at room temperature?
1. \(1.1~\text{eV}\)
2. \(0.1~\text{eV}\)
3. \(0.67~\text{eV}\)
4. \(6.7~\text{eV}\)
To unlock all the explanations of this course, you need to be enrolled.
To unlock all the explanations of this course, you need to be enrolled.
Which of the energy band diagrams shown in the figure corresponds to that of a semiconductor?
| 1. |  |
2. |  |
| 3. |  |
4. |  |
To unlock all the explanations of this course, you need to be enrolled.
To unlock all the explanations of this course, you need to be enrolled.
A semiconductor is known to have an electron concentration of \(8\times 10^{13}~\text{cm}^{-3}\) and a hole concentration of \(5\times 10^{2}~\text{cm}^{-3}\). The semiconductor is:
| 1. | \(\mathrm{n}\text-\)type | 2. | \(\mathrm{p}\text-\)type |
| 3. | intrinsic | 4. | insulator |
To unlock all the explanations of this course, you need to be enrolled.
To unlock all the explanations of this course, you need to be enrolled.
© 2024 GoodEd Technologies Pvt. Ltd.