List of top Physics Questions on Semiconductor electronics: materials, devices and simple circuits asked in KEAM

Choose the correct statement
In an n-p-n transistor, the majority charge carriers in the emitter are
In a forward biased semiconductor potential changes from 0.9V to 0.6 V. Find current if resistance is $1\Omega$
In a semiconductor crystal, the total number of electrons in the outer shell is 4N . At absolute zero, the number of energy states of valence and conduction band are respectively
In a p-n junction diode, reverse biasing
Which one of the following is not a semiconductor?
A block of mass \( M \) is placed on the floor of a lift at the center. The acceleration required for the lift to descend so that the block exerts a force of \( \frac{Mg}{4} \) on the lift floor is:
A tennis ball of mass 50g thrown vertically up at a speed of 25 m s\(^{-1}\) reaches a maximum height of 25 m. The work done by the resistance forces on the ball is:
For a given radioactive material of mean life \(\tau\) and half-life \(t_{1/2}\), the relationship between \(t_{1/2}\) and \(\tau\) is:
A car moving with a speed \( v \) is stopped at a distance \( d \) by a retarding force \( F \). The force needed to stop the same car moving with the speed \( 3v \) within the same distance is:
A balloon of mass 60 g is moving up with an acceleration of 4 m/s\(^2\). The mass to be added to the balloon to descend it down with the same acceleration is (g = 10 m/s\(^2\)):
If a planet orbits the Sun in an elliptical orbit, the quantities associated with the planet that remain constant are:
The quantity of heat conducted through a metal rod kept at its ends at 100°C and 120°C is 5 J/s. If the ends are kept at 200°C and 220°C, then the quantity of heat conducted in 10 seconds is:

A NOR gate has two input I1 and l2,and one output terminal Y. Which of the following configuration (truth table) is INCORRECT for the NOR gate?

In a Zener regulated power supply circuit as shown in figure below,a Zener diode with Vz=1OV is used for regulation. The load current,Zener current and unregulated input Vin are 5mA,35mA and 20V,respectively. The value of R is:
The special purpose diode operated / working under forward bias is / are
The compound semiconductor used for making LEDs of different colours is
Identify the mismatched pair from the following
If the rms value of sinusoidal input to a full wave rectifier is $\frac{V_0} { \sqrt{2}}$ then the rms value of the rectifier?s output is
Mobility is the ratio of drift velocity and ________?
A common emitter amplifier gives an output of $ 3 \,V $ for an input of $ 0.01 \,V $ . If $ \beta $ of the transistor is $100$ and the input resistance is $ 1\text{ }k\Omega , $ then the collector resistance is
In n- p-n transistor, the collector current is 10 mA. If 90% of the electrons emitted reach the collector, then
The electrical conductivity of an intrinsic semiconductor at 0K is
For a Zener diode