Electronic Science - Online Test
Q1. A p-n junction has a thickness of the order of
Answer : Option B
Explaination / Solution:
The width of depletion layer depends on the nature of semiconductor and doping concentration of the two sides of p-n junction. If the doping concentration is small, the width of p-n junction is large and vice-versa. Thus the width of p-n junction will be of the order of to .
Q2.
In a uniformly doped BJT, assume that NE, NB and NC are the emitter, base and collector doping in atoms/cm3, respectively. If the emitter injection efficiency of the BJT is close unity, which one of the following condition is TRUE
Answer : Option B
Explaination / Solution:
Emitter injection efficiency is given as
Q3. The following Karnaugh map represent a function F.
A minimized form of the function F is
Answer : Option B
Explaination / Solution:
No Explaination.
Q4. In the figure shown, all elements used are ideal. For time t<0, S1 remained closed and S2 open.
At t = 0, S1 is opened and S2 is closed. If the voltage Vc2 across the capacitor C2 at t = 0 is zero,
the voltage across the capacitor combination at t=0+ will be
Answer : Option C
Explaination / Solution:
Q5. In the following circuit, the input voltage Vin is 100
sin(100πt). For 100πRC = 50, the
average voltages across R (in volts) under steady-state is nearest to
Answer : Option C
Explaination / Solution:
Given circuit is voltage doubler
Vm = Voltage across each capacitor = 100V
Voltage across two capacitors (in steady state)
= 2Vm = 200V
Q6. The amount of energy a capacitor can store is called its
Answer : Option B
Explaination / Solution:
Energy stored in a capacitor
Q7. A good current buffer has
Answer : Option B
Explaination / Solution:
No Explaination.
Q8. Electromotive force is
Answer : Option A
Explaination / Solution:
An electric field exists in the electrolyte between the positive and negative terminals of the battery. In the external circuit, the current flows from the positive electrode to the negative electrode. To maintain continuity, in the electrolyte, the current (positive charges) flow from the negative electrode (lower potential) to the positive electrode (higher potential). Work done by the source in taking unit positive charge from lower to higher potential is called electromotive force.
Q9. In a coil of 0.1 m radius and 100 turns, 0.1 amp current is passed. What will be the magnetic field at the centre of the coil
Answer : Option C
Explaination / Solution:
Q10. Nitric oxide is a paramagnetic compound. The magnetic moment of each NO molecule has a maximum component in any direction of about one Bohr magneton.Interaction energy of such magnetic moments in a 1.5-T magnetic field is
Answer : Option A
Explaination / Solution:
No Explaination.
