WorksheetsELC1
Total questions: 128
Worksheet time: 2hrs 36mins
Gate of MOSFET is insulated with layer of...?
SiO2
O2
Si
None
What is the full form of IGBT...?
Insulation gate bipolar transistor
Insulation gate bidirectional transistor
Insulated gate bipolar transistor
Insulated gate bidirectional transistor
PWM in voltage source inverter can control ----------------------- of the voltage output ?
Frequency
Magnitude
Both Frequency & Magnitude
None
Static UPS requires...?
Only Rectifier
Only Inverter
Both Rectifier & Inverter
None
Which device can be used in a chopper circuit?
GTO
IGBT
MOSFET
ALL
Generally for a pure Inductive load what is the impedance angle φ?
120 degree
90 degree
180 degree
270 degree
Which device can be used in a chopper circuit?
GTO
IGBT
MOSFET
ALL
Which device can be used in a chopper circuit?
GTO
IGBT
MOSFET
ALL
A silicon controlled rectifier (SCR) is a-----------
Unijunction device
Device with three junction
Device with four junction
None of the above
A thyristor is basically
PNPN device
A combination of diac and triac
A set of SCRs
A set of SCR, diac and a triac
Which semiconductor power device out of the following, is not a current triggering device?
Thyristor
Triac
G.T.O
MOSFET
Which of the following device incorporates a terminal for synchronizing purposes?
Diac
Triac
Silicon Unilateral Switch (SUS)
None of the above
The advantages of SCS over SCR is
Slow switching time and large VH
Slow switching time and smaller VH
Faster switching time and smaller VH
Faster switching time and large VH
A thyristor equivalent of a thyratron tube is a
Diac
Triac
Silicon controlled rectifier
None of the above
A triac is a
2 terminal switch
2 terminal bilateral switch
3 terminal bilateral switch
3 terminal bidirectional switch
The fig. above represents a
Triac thyristor
Diac trigger
Diode rectifier
None of the above
A device that cannot be triggered with low voltage of either polarity is
Diac
Triac
SCS
All of the above
The fig. given above represents
Silicon controlled rectifier
Field effect transistor
Photoemissive diode
Tunnel diode
The given fig. represents
Triac thyristor
Diac thyristor
Capacitive Diode
None of the above
A device that does not exhibit negative resistance characteristics is
FET
UJT
Tunnel diode
SCR
A triac
Conducts when not triggered
Conducts when not triggered in both direction
Conducts when triggered in one direction
None of the above
For a thyristor shown is
All the 3 junctions are forward Biased
J1, J2 are forward biased and j3 reversed biased
J1 is forward biased, J2, J3 reversed biased
J1, J2 are reversed biased J3 is forward biased
The thyristor is turned -off when the anode current falls below_____
Forward current
Latching current
Holding current
Breakover current
In a thyristor circuit, the angle of conduction is changed by changing______
Anode voltage
Gate current
Forward current
Anode current
The VI characteristics of UJT is
Similar to CE with a linear and saturation region
Similar to FET with a linear and pinch off region
Similar to tunnel diode in some respects
Similar to PN junction diode in some respects
UJT when used for triggering an SCR, has the waveform
Sine wave
Square Wave
Sawtooth wave
Trapezoidal
A resistor connected across the gate and cathode of a thyristor increase its
Turn off time
di/dt rating
Noise immunity
Holding current
P-side emitter in UJT is
Not doped
Feebly doped
Heavily doped
Moderately doped
Inverter converts
DC to AC
AC to DC
DC to DC
AC to AC
When thyristor and transistor as a switch are compared, the true statement is
Thyristor requires turns off circuit while transistor does not
The voltage drop of the thyristor is less than transistor
Thyristor requires a continuous gate current
Transistor does not draw continuously base current
When emitter terminal of a UJT is open then the resistance of the base terminal is
Very high
Very low
Moderate
Any finite value
If the firing angle in an SCR rectifier is decreased, the output is
Increased
Maximum
Decreased
Remain Unaffected
A SCR is a ________ switch
One directional
Two directional
Three directional
Four Directional
Comparing a triac & SCR
Both are unidirectional devices
An SCR has less time for turn off than Triac
Both are bidirectional devices
All of the above
Which of the following statement is true about Thyristor
The turn off time of a thyristor is less than the turn-on time
The turn-on time is less than the turn-off time
The turn-off time for the line commutation is less than the forced commutation
None of the above
The figure represents
Zener diode
Silicon controlled rectifier
Junction field effect transistor
Tunnel diode
Among this alternative, PIV rating of which diode is lower than that of equivalent vacuum diode?
PN Junction Diode
Crystal Diode
Tunnel Diode
Small single Diode
A forward bias PN junction will act as a/an:
Amplifier
Open switch
Closed Switch
Attenuator
What type of Machine Learning Algorithm is suitable for predicting the continuous dependent variable?
Logistic Regression
Linear Regression
Decision Tree Classifier
KNN Classifier
What type of Machine Learning Algorithm is suitable for predicting the dependent variable with two different values?
Logistic Regression
Linear Regression
Multiple Linear Regression
Polynomial Regression
The correlation in between mobile usage and exam score of a person found to be -2.2. What is your inference from the above statement.
Mobile usage is positively correlated with exam score
Mobile usage is negatively correlated with exam score
None of the mentioned
Need some other information
The residual is the difference in between ________________
actual value of y and the estimated value of y
actual value of x and the estimated value of x
actual value of y and the estimated value of x
actual value of x and the estimated value of y
Suitable evaluation metric for measuring the performance of a given regression model is
Mean Absolute Error
Root Mean Square Error
Precision
Recall
If we decrease the input variable by one unit in a simple linear regression model. How many units of the output variable will change?
reduced by Intercept
increased by Intercept
increased by Slope
reduced by Slope
Appropriate chart for visualizing the linear relationship between two variables is _________________
Scatter plot
Barchart
Histograms
None of Mentioned
The Number of coefficients required to estimate a simple linear regression?
1
2
0
3
KNN Algorithm can be used for
Only for Classification
Only for Regression
Both Classification and Regression
None of the Mentioned
KNN is ___________ algorithm
Non-parametric and Lazy Learning
Parametric and Lazy Learning
Parametric and Eager Learning
Non-parametric and Eager Learning
What kind of distance metric(s) are suitable for categorical variables to finding the closest neighbors
Euclidean Distance
Manhattan distance
Minkowski distance
Hamming distance
What kind of distance metric(s) are suitable for continuous variables to find the closest neighbors
Euclidean Distance
Manhattan distance
Minkowski distance
Hamming distance
KNN algorithm appropriate for
Lower number of features
Large number of features
No such restriction on number of features
None of the Mentioned
KNN algorithm requires
More time for training
More time for testing
Equal time for training and testing
None of the Mentioned
The entropy of a given dataset is zero. This statement implies what?
further splitting is required
no further splitting is required
Need some other information to decide splitting
None of the Mentioned
If the given dataset contains 100 observations out of 50 belongs to class1 and other 50 belongs to class2. What will be the entropy of the given dataset?
0
1
-1
0.5
How do you choose the root node while constructing a Decision Tree?
An attribute having high entropy
An attribute having largest information gain
An attribute having high entropy and Information gain
None of the Mentioned
Chose the correct criterion for Decision Tree Classifier in sklearn package
Gini
Entropy
Information Gain
Random
In a Decision Tree Leaf Node represents_____________
One of the Class Label
One of the complete observation
One of the attribute
None of the Mentioned
Consider the above Confusion Matrix of a classifier and choose the correct statements
Accuracy is 84%
Misclassification Rate is 16%
Type-I Error is 6
Type-II Error is 10
According to Tom Mitchell, what is the requirement for the computer system to learn
Data set
Task
Performance measure
Knowledge
Select a possible application of the machine learning
Fraud detection
Recognising a happy face
Differentiate X-ray image
Recognise your lecturer's hand writing
To recognise the face as an object, the image of face is breakdown into combination of edges, edges, and pixel.
True
False
What is the implication of "false positive" increase to the precision measure
increase precision
decrease precision
doesn't has any effect to precision
What is the implication of decreasing "false negative" to the recall measure
decreasing recall
increasing recall
doesn't have any effect to recall
In the case of pregnancy prediction, if the predictor output is always "pregnant" what is the recall value?
1
0
0.1
Undefined
In the case of pregnancy prediction, if the predictor output is always "not pregnant" what is the precision value?
1
0
0.5
Undefined
The unsupervised learning is better used for prediction
True
False
Artificial neural network consists of following fundamental components
Neurons as nodes
Synapses as weight
Neurons as weight
Synapses as nodes
Supervised learning used rewards, training data, and desired output
True
False
Suppose your email program watches which emails you do or do not mark as spam, and based on that learns how to better filter spam. What is the task T in this setting?
Classifying emails as spam or not spam
Watching you label emails as spam or not spam
The number of emails correctly classified as spam/not spam
None of the above
You are running a company and you want to develop learning algorithms to address each of two problems.
Problems 1: you have a large inventory of identical items. you want to predict how many of these items will sell over the next 3 months.
Problem 2: you would like software to examine individual customer accounts and for each account decide if it has been hacked/compromised.
Should you treat these as classification or as regression problems?
Treat both as classification problems
Treat problem 1 as classification and problem 2 as regression
Treat problem 1 as regression and problem 2 as classification
Treat both as regression problems
Of the following examples, which would you address using an unsupervised learning algorithm? check all that apply
Given email labeled as spam/not spam, learn a spam filter
Given a set of news articles found on the web, group them into set of articles about the same story
Given a database of customer data, automatically discover market segments and group customers into different market segments
Given a dataset of patients diagnosed as either having diabetes or not, learn to classify new patients as having diabetes or not
In the "model representation", Andrew Ng uses variable "m" to represent
number of training example
input variable
output variable
feature
Machine learning is mostly used when
Human expertise doesn't exist
Model must be customised to personal need
Model use huge amount of data
Interpreting the insight from descriptive data such as mean, median etc
In serial communication data is send as-------bit at a time
8
2
1
16
Most reliable Data communication
serial
parallel
Which one is quick data transfer method
Serial
Parallel
Expensive data communication method
Synchronous
Asynchronous
The 2 pins used for data communication in MC 8051
(a)
Format of data in digital data transmission
(a)
In which data transmission method multiple data bits are transmitted over multiple channels
serial
parallel
Example of asynchronous communication
UART
USART
In which data communication method the events are referenced to clock
asynchronous
synchronous
In which serial communication method the bytes are separated by START & STOP bits
Asynchronous
Synchronous
List two Special function registers used for Serial communication in MC8051
(a)
Give the full form of SBUF Register
(a)
The size of SCON register
8 bit
16 bit
2 bit
1 bit
Which is multiprocessor communication bit in SCON
SM0
SM1
SMOD
SM2
Which Interrupt flag is set to indicate completed data transfer
RI
TI
Which Interrupt flag is set to indicate completed data Reception
RI
TI
Which is serial communication baud rate modify bit
PD
SM2
SMOD
Which is the power control register in MC8051
SCON
PCON
SBUF
How many modes are there in the serial data communication in MC8051
1
2
3
4
Which pin provides clock in Mode0
TXD
RXD
INT0
Which mode is half duplex communication
0
2
1
Data format in mode 2
8
10
11
Data format in mode0
8
10
11
Data format in mode1
8
11
10
whenSM2=1 in mode2 slaves will consider received byte as
address
data
To increase damping of pair of complex roots compensator used is
Phase lag
Phase lead
Phase lag lead
One with 60° lead circuit
If poles of system are lying on the imaginary axis in s-plane, the system will be
Unstable
Marginally stable
Conditionally stable
Unstable
Which system conveniently see the impact of poles and zeros on phase and gain margin?
Root locus
Nyquist plot
Routh-Hurwitz criterion
Bode plot
To study time delay of the system which of the following is used?
Nyquist plot
Bode plot
Routh Hurwitz method
Nicholas chart
Closed loop poles are
Zeros of 1+G(S). H(s)
Zeros of G(s) H(s)
Poles of G(s) H(s)
Poles of 1 + G(s) H(s)
Feed back control system are basically
Low pass filter
High pass filter
Band pass filter
Band stop filter
Plot of the constant gain loci of the system is
Asymptote
Circle with centre at the origin
Parabola
Ellipse
Frequency response means
Transient response of a system to a sinusoidal input
Steady state response of a system to a sinusoidal input
Oscillatory response of a system to a sinusoidal input
None of these
Gain margin expressed in decibels is
Positive if Kg greater than 1 and negative for Kg less than 1
Negative if Kg greater than 1 and negative for Kg less than 1
Always zero
Infinity for Kg equal to 1
In Nyquist criterion roots of the characteristic equation are given by
Zeros of open loop transfer function
Zeros of closed loop transfer function
Poles of closed loop transfer function
Poles of open loop transfer function
For relative stability of the system which of the following is sufficient?
Gain margin
Phase margin
Both (a) and (b)
None of these
For G(S) F(S) = (k(S+z))/(S+p), (z < p) the plot is
One pole on the imaginary axis
One zero on the right-hand side of the plane
2 poles and 2 zeros on the left-hand side of plane
One pole and one zero on the left-hand side of plane
Bode analysis method can be applied
If transfer function has no poles and zeros on R.H. of s-plane
If transfer function has no poles on R.H. of s-plane
If transfer function has no zero on R.H. of s-plane
To all transfer functions
Cut off is the slope of log-magnitude curve
At the start of curve
At the end of curve
None of these
Near the cut off frequency
Slope in Bode plot is expressed as
– 6 db/decade
– 6 db/octave
– 7 db/octave
– 8 db/octave
Polar plots for+ve and –ve frequencies
Are always symmetrical
Can never be symmetrical
May be symmetrical
None of these
According to the property of state transition method, e0 is equal to _____
I
A
e-At
-eAt
Which mechanism in control engineering implies an ability to measure the state by taking measurements at output?
Controllability
Observability
Differentiability
Adaptability
State model representation is possible using _________
Physical variables
Phase variables
Canonical state variables
All of the above
State space analysis is applicable even if the initial conditions are _____
Zero
Non equal
Equal
Not zero
