MEPCO: Communication,electronics, DSP, control, microwave
We built control systems for _______
1. Power amplification 2. Remote control 3. Convenience of input form 4. Compensation for disturbances
Cross over distortion is problem in __________ class of amplifiers
Class B
Horizontal line in the s plane represents_______
Constant damping
digital multimeter is a combination of ?
DC voltmeter, AC voltmeter, ammeter, ohmmeter
Common mode rejection ratio is the ratio of
Differential mode gain to Common Mode gain
A digital signal is what in A. Dicrete B. Discrete in time C. Discrete in amplitude D. Discrete in neather time nor amplitude E. Discrete in both amplitude and time
Discrete in both amplitude and time
The channel of a JFET is between the A. Gate and drain B. Drain and source C. Gate and source D. Input and output
Drain and source
Kilowatt hour is the unit of (this was repeated two times)
Energy
Signal with different frequency and sampling rate are time division multiplexed by ________ a. FDM b. Synchronous Multiplexing c. Pulse Stiffing
FDM
The wavelength of an EM wave after reflection at an angle on a surface
Increases in the actual direction of propagation
Transfer function is A. Mathematical model B. System with no physical structure C. Can be calculated through differential equations
Mathematical model
Δ x H = J + D is?
Maxwell equation
Continuous signal in the time domain is ____ in frequency domain?
It is sum of infinite exponentials
fault analysis is done by ?
Jordan principle
For measuring small resistance we use
Kelvin bridge
A _____ meter is used a null detector in wheatstone bridge A. Ammeter B. Voltmeter C. Galvanometer
Voltmeter
bridge used for the measurement of resistance
Wheatstone bridge
A moving iron ammeter coil has few turns of thick wire in order to have: A. Low resistance B. High sentivity C. Effective damping D. Large scale
low resistance
Function of diode is__________
rectification
If pole is in left half of s plane system is.........
stable
What is zero in resonance circuit?
zeries(reactance)
_____acts as voltage controlled variable capacitor
Varactor
________ diode is used as voltage controlled capacitor.
Varactors
An Ideal voltage source has internal resistance
0Ω Resistance
What will be the sampling frequency that reveals the same sampled signal
2Fmax
When the current decreases to 2% the power in bulb decrease to______?
4%
In z transform cos pi/4 is the period is equal to
8pi
____ is defined as the measure of instrument by which it is error free A. Accuracy B. Precision C. Resolution
Accuracy
Which transistors are used in TTL?
Bjts ransistor-transistor logic (TTL) is a class of digital circuits built from bipolar junction transistors (BJT) and resistors. It is called transistor-transistor logic because both the logic gating function (e.g., AND) and the amplifying function are performed by transistors (contrast with resistor-transistor logic (RTL) and diode-transistor logic (DTL)).
DC to DC with high voltage gain ______
Boost (uses mosfet)
If poles and zeroes are within unit circle then A. System is stable B. Inverse of system is stable C. Both system and its inverse are unstable D. Both system and its inverse are stable
Both system and its inverse are stable
By connecting a shunt of higher value in ammeter __________ will decrease
Current sensitivity decreases
If ROC (Region of Convergence) does not converge then A. Z transform does not exist B. Fourier transform does not exist
Fourier transform does not exist
Main feature of crystal diode _________ a. Stability b. Reliability c. High frequency
High Frequency Crystal diode is also called as a Cat's-whisker diode or Point-contact diode or Crystals. These diodes microwave-semiconductor devices were developed during the World War II to be used in the microwave receivers and detectors.
In LTI system is characterized by A. Impulse input B. Step input
Impulse input
Hay bridge is used for the measurement of
Inductance
Superposition theorem relates to which system?
Linear system
The EM field and current are concentrated close to the surface of the conductor. The phenomenon is called?
Skin Effect
A diode that has a negative resistance characteristics is the A. Schottkey diode B. Tunnel diode C. Hot-carrier diode D. Laser diode E. Zener Diode
Tunnel diode
Output of system depends only on present or past value not on future value, then system is said to be
causal
in z transform, ROC is centred at____
origin
What is max in resonance ckt......
series (current)
Which type of system is referred by pneumatic system A. Pressure B. Hydraulic C. Fluid
Pressure
Electrical lines of force about a negative charge are? A. Circular, anticlockwise B. Circular, clockwise C. Radial, inward D. Radial, outward
Radial, inward
Due to voltage saturation, MOSFET enters in
Saturation region
Natural frequency in the control system represents
Transient response
fastest damping possible without overshoot in ____
criticaly damped system
If R1 is the resistance of a coil of copper at t oC and RT is the resistance at T oC and also the resistance temperature coefficient of copper per degree centrigrade at 0oC is 1/234.45, then Rt/RT (A) (1+t) / (1+T) (B) (1+ 234.45t) / (1+234.45 T) (C) (234.45 + t) / (234.45 + T) (D) (234.45 + t2 ) / (234.45 + T 2).
(234.45 + t) / (234.45 + T)
Modulation techniques in which carrier is switched between two different carrier levels _________
On/off keying
Resolution of ADC is defined as the no. of bits in_____
Output
An Ideal current source has internal resistance
∞Ω Resistance or open circuit
