Advertisements
Advertisements
प्रश्न
When the base current in a transistor is changed from 30µA to 80µA, the collector current is changed from 1.0 mA to 3.5 mA. Find the current gain β.
Advertisements
उत्तर
Given:
Change in the base current, \[\delta I_b = (80 - 30) \mu \text{A}\]
Change in the collector current, \[\delta I_c = (3 . 5 - 1) \] mA
Thus,
\[\beta = \left( \frac{\delta l_c}{\delta l_b} \right) \text{at constant V}_{cc} \]
\[ \Rightarrow \beta = \frac{2 . 5 \times {10}^{- 3}}{50 \times {10}^{- 6}}\]
\[ \Rightarrow \beta = \frac{250}{50} = 50\]
APPEARS IN
संबंधित प्रश्न
In a p-n junction diode, the current I can be expressed as
I = `"I"_0 exp ("eV"/(2"k"_"BT") - 1)`
where I0 is called the reverse saturation current, V is the voltage across the diode and is positive for forward bias and negative for reverse bias, and I is the current through the diode, kBis the Boltzmann constant (8.6×10−5 eV/K) and T is the absolute temperature. If for a given diode I0 = 5 × 10−12 A and T = 300 K, then
(a) What will be the forward current at a forward voltage of 0.6 V?
(b) What will be the increase in the current if the voltage across the diode is increased to 0.7 V?
(c) What is the dynamic resistance?
(d) What will be the current if reverse bias voltage changes from 1 V to 2 V?
A zener diode is fabricated by heavily doping both p- and n- sides of the junction. Explain, why?
Explain briefly with the help of necessary diagrams, the reverse biasing of a p-n junction diode. Also draw characteristic curves.
Mention the important considerations required while fabricating a p-n junction diode to be used as a Light Emitting Diode (LED). What should be the order of band gap of an LED if it is required to emit light in the visible range?
Explain, with the help of a circuit diagram, the working of n-p-n transistor as a common emitter amplifier.
Diffusion current in a p-n junction is greater than the drift current in magnitude
Two identical p-n junction may be connected in series with a battery in three ways. The potential difference across the two p-n junctions are equal in

In a p-n junction with open ends,
(a) there is no systematic motion of charge carries
(b) holes and conduction electrons systematically go from the p-side to n-side and from the n-side to p-side respectively
(c) there is no net charge transfer between the two sides
(d) there is a constant electric field near the junction.
In a p-n junction,
(a) new holes and conduction electrons are produced continuously throughout the material
(b) new holes and conduction electrons are produced continuously throughout the material except in the depletion region
(c) holes and conduction electrons recombine continuously throughout the material
(d) holes and conduction electrons recombine continuously throughout the material except in the depletion region.
A semiconducting device is connected in a series circuit with a battery and a resistance. A current is found to pass through the circuit. If the polarity of the battery is reversed, the current drops to almost zero. the device may be
(a) an intrinsic semiconductor
(b) a p-type semiconductor
(c) an n-type semiconductor
(d) a p-n junction
In a p.n junction, the depletion region is 400 nm wide and an electric field of 5 × 105 V m−1 exists in it. (a) Find the height of the potential barrier. (b) What should be the minimum kinetic energy of a conduction electron which can diffuse from the n-side to the p-side?
The drift current in a p-n junction is 20.0 µA. Estimate the number of electrons crossing a cross section per second in the depletion region.
Find the currents through the resistance in the circuits shown in figure.

(Assume that the resistance of each diode is zero in forward bias and is infinity in reverse bias.)
Find the current through the resistance R in figure if (a) R = 12Ω (b) R = 48Ω.

(Assume that the resistance of each diode is zero in forward bias and is infinity in reverse bias.)
An AC source is connected to a diode and a resistor in series. Is the current thorough the resistor AC or DC?
Choose the correct option.
Current through a reverse-biased p-n junction increases abruptly at:
The depletion layer in the p-n junction diode is caused by ______.
