Question { 20850 }

What is CMRR? Explain briefly.

Answer

CMRR(common mode
rejection ratio) is the ratio of
differential mode gain to the
common mode gain. Actually
in differential amplifier it
should amplify the difference
of the two input signals and
reject the common signals
applied at both ends. CMRR
indicates the efficiancy of the
differential amplifier. Ideally
the CMRR value must be
infinite

Question { Assurgent, 13235 }

modulation means

Answer

Modulation is process of varying the parameters of high frequency signal(carrier signal) like amplitude,frequency and phase with respect to low frequency signal(message signal i.e signal that is gonna transmitted)

Question { TCS, 26089 }

wat s the difference between diode and capacitor

Answer

Diode is an electronic device
which is made of
semiconducting material
normally silicon or
germanium and the purpose
of diode is it can act as a
switch(it allows flow of
electrons in one direction
and opposes in another
direction) and as a device in
rectifier(AC-DC). Capacitor is a
device which is used to store
the charges as well as to
oppose DC to pass through
it.

Question { IBM, 36500 }

why AC cannot to be stored and DC cannot be transmitted?

Answer

AC cant be stored because as
it changes at every instant of
time but we can charge it
upto half cycle and another it
discharges. Actually dc is not
transmitted because various
energy sources develop AC
which is of high value and
since our electronic devices
work for the constant value
we convert it to a small value
by means of rectifiers,filters
and regulators. Another
reason for not transmitting
dc is we cant step up or step
down it by means of
transformer.

Question { 13205 }

what is TRANSDUCERS?

Answer

Transducers are the devices
which are used to covert non
electrical form of energy into
electrical form of energy

Question { 6179 }

what is difference between voltage & current?

Answer

Current is flow of electrons in the conductor.
Voltage is the force applied to move the electrons.

Question { 7262 }

what is need of modulation & de-modulation in communication?

Answer

modulation is the process of changing the characteristics of
high frequency signal (carrier signal) like
amplitude,phase,frequency with reference to a low frequency
signal(message signal).
Need of modulation is 1.To decrease the antenna height
*to transmit a low frequency signal we need height of
antenna to be very large(since wavelength is inversly
proportional to frequency.so if we modulate a low frequency
signal with a high frequency one then it requires antenna
height of just meters,which is practically possible.
2.To avoid interference in the channel we adopt modulation.
3.To overcome noise in the channel.
Demodulation is necessary to retrive back the message signal
from modulated signal.

Question { 6416 }

what is resister

Answer

Resistor is one of the passive element which is used to oppose
the flow of electrons(current)in the conductor.

Question { 6731 }

what is the physical meaning of a hole in pn junction
diode ???do they actually move?

Answer

It is known that on applying
voltage on the
semiconductor electrons
from the valency band cross
the junction and pass into
conduction band. These
electrons create holes in
valency band. This is how
conduction takes place.

Question { HSBC, 22837 }

is transformer, active or passive device?
name some active and passive devices.

Answer

Active elements:Elements those deliver power or energy to
other devices
ex are voltage and current sources
Passive elements:Elements those receive the power or energy
from active elements
ex are resistance ,inductance,capacitence

Question { Dream Careers, 8493 }

what is oscillator?

Answer

Oscillators are the devices which are used to convert DC to AC
It also has positive feedback so it is also called an
amplifier because it produces output upon adding the positive
feedback.

Question { ABB, 7707 }

what is electronics?

Answer

Electronics is the technology of controlling the flow of electrons.

Question { 7503 }

why all electronic devices works on DC

Answer

DC is a constant source
generator and all our
electronic devices require a
constant supply to operate
suppose if we consider AC its
vaule change at every instant
of time. Normally all electronic
devices has specific vaule to
operate if it increases further
then the device may damage
so as DC is constant the
devices operate on it by
converting AC into DC by the
rectifiers.

Question { 8624 }

By cascading LPF and HPF active filter, the resulting
circuit is
A BPF B Narrow BPF
C Wide BPF D All of these

Answer

C.wide BPF

Question { Hindalco, 7287 }

whah is active and passive components?

Answer

Elements capable of delivering their power and energy to other elements are Active compenents. Ex are current and voltage sources
Elements who receive the energy from active components are called passive elements.Ex resistor,capacitors and inductors