Prepare for your Electronics and Communication Engineering exams/aptitude tests, assess your knowledge of electronics and communication equipment with these ECE questions and answers.
In an n-p-n transistor, the majority carriers in the base are
electrons
holes
both holes and electrons
either holes or electrons
Correct answer is A
Emitter is n type and emits electrons which diffuse through the base.
0.5 eV above valence band
0.28 eV above valence band
0.1 eV above valence band
below the valence band
Correct answer is B
Addition of acceptor atom brings Fermi level closer to valence band.
low copper loss
low eddy current loss
low resistivity
higher specific gravity compared to iron
Correct answer is C
Ferrite is a low density material of composition with Fe2O3 x O, where x is a bivalent metal, such as Cobart, Ni, Mn. These magnetic materials have very low loss of current and used in high frequency circuit.
When a voltage is applied to a semiconductor crystal, then the free electrons will flow
towards positive terminal
towards negative terminal
either towards positive terminal or negative terminal
towards positive terminal for 1 μs and towards negative terminal for next 1 μs
Correct answer is A
Since electrons are negatively charged they will flow towards positive terminal.
At very high temperatures, the extrinsic semi conductors become intrinsic because
of drive in diffusion of dopants and carriers
band to band transition dominates over impurity ionization
impurity ionization dominates over band to band transition
band to band transition is balanced by impurity ionization
Correct answer is B
Covalent bonds are broken.