In the circuit shown in the figure, the input voltage Vi is 20 V, VBE = 0, and VCE = 0. The values of IB, IC and are given by:
1.
2.
3.
4.
In a \(\mathrm{p\text{-}n}\) junction diode, the change in temperature due to heating:
| 1. | affects only reverse resistance. |
| 2. | affects only forward bias. |
| 3. | does not affect the resistance of the \(\mathrm{p\text{-}n}\) junction. |
| 4. | affects the overall \(\mathrm{V\text{-}I}\) characteristics of a \(\mathrm{p\text{-}n}\) junction. |
| 1. | \(r^3\) | 2. | \(r^2\) |
| 3. | \(r^5\) | 4. | \(r^4\) |
A sample of \(0.1\) g of water at \(100^{\circ}\mathrm{C}\) and normal pressure (\(1.013 \times10^5\) N m–2) requires \(54\) cal of heat energy to convert it into steam at \(100^{\circ}\mathrm{C}\). If the volume of the steam produced is \(167.1\) cc, then the change in internal energy of the sample will be:
| 1. | \(104.3\) J | 2. | \(208.7\) J |
| 3. | \(42.2\) J | 4. | \(84.5\) J |
Two wires are made of the same material and have the same volume. The first wire has a cross-sectional area \(A\) and the second wire has a cross-sectional area \(3A\). If the length of the first wire is increased by \(\Delta l\) on applying a force \(F\), how much force is needed to stretch the second wire by the same amount?
| 1. | \(9F\) | 2. | \(6F\) |
| 3. | \(4F\) | 4. | \(F\) |
The power radiated by a black body is \(P\) and it radiates maximum energy at wavelength \(\lambda_0.\)
| 1. | \( \dfrac{3}{4} \) | 2. | \( \dfrac{4}{3} \) |
| 3. | \( \dfrac{256}{81} \) | 4. | \( \dfrac{81}{256}\) |
A set of '\(n\)' equal resistors, of value '\(R\)' each, are connected in series to a battery of emf '\(E\)' and internal resistance '\(R\)'. The current drawn is \(I.\) Now, if '\(n\)' resistors are connected in parallel to the same battery, then the current drawn becomes \(10I.\) The value of '\(n\)' is:
1. \(10\)
2. \(11\)
3. \(20\)
4. \(9\)
A battery consists of a variable number \(n\) of identical cells (having internal resistance \(r\) each) which are connected in series. The terminals of the battery are short-circuited and the current \(I\) is measured. Which of the graphs shows the correct relationship between \(I\) and \(n?\)
| 1. | 2. | ||
| 3. | 4. |
A carbon resistor (47 ± 4.7) kΩ is to be marked with rings of different colours for its identification. The colour code sequence will be:
1. Violet - Yellow - Orange - Silver
2. Yellow - Violet - Orange - Silver
3. Yellow - Green - Violet - Gold
4. Green - Orange - Violet - Gold
Which one of the following statements is incorrect?
| 1. | Rolling friction is smaller than sliding friction. |
| 2. | The limiting value of static friction is directly proportional to the normal reaction. |
| 3. | Frictional force opposes the relative motion. |
| 4. | The coefficient of sliding friction has dimensions of length. |