221.
An SCR can exercise control over ………. of a.c. supply
A
Negative half-cycles only
B
Both positive and negative half-cycles
C
Positive or negative half-cycles
D
Positive half-cycles only
Loading practice questions
Browse topic-based Electrical and Electronics practice sets.
1594 practice sets · Page 12 of 80
An SCR can exercise control over ………. of a.c. supply
Negative half-cycles only
Both positive and negative half-cycles
Positive or negative half-cycles
Positive half-cycles only
In normal operation of an SCR, gate is ………..w.r.t. cathode
Negative
At zero potential
None of the above
Positive
An SCR is made of silicon and not germanium because silicon ………
Is mechanically strong
Has small leakage current
Is tetravalent
Is inexpensive
If gate current is increased, then anode-cathode voltage at which SCR turns ON
is increased
remains the same
none of the above
is decreased
If gate current is increased, then anode-cathode voltage at which SCR closes …………….
Is increased
Remains the same
None of the above
Is decreased
An SCR is made of ………….
Silicon
Carbon
None of the above
Germanium
When SCR starts conducting, then …………… loses all control
Cathode
Anode
None of the above
Gate
When SCR is OFF, the current in the circuit is …………….
Small leakage current
Large leakage current
None of the above
Exactly zero
In an SCR circuit the supply voltage is generally ……….. that of breakover voltage
Equal to
Less than
Greater than
None of the above
In an SCR circuit, the angle of conduction can be changed by ……….
Changing anode voltage
Changing gate voltage
Reverse biasing the gate
None of the above
An SCR has three terminals viz ……………
Cathode, anode, gate
Anode, cathode, grid
Anode, cathode, drain
None of the above
When SCR starts conducting, which loses all control?
Cathode
Gate
Anode
None of the above
The control element of an SCR is ………….
Cathode
Anode
Anode supply
Gate
The normal way to turn on a SCR is by ……………..
Breakover voltage
Appropriate anode current
Appropriate gate current
None of the above
With gate open, the maximum anode current at which SCR is turned off from ON condition is called
breakdown voltage
peak reverse voltage
holding current
latching current
In the normal operation of an SCR, anode is …………… w.r.t. cathode
At zero potential
Negative
Positive
None of the above
An SCR is turned off when …………..
Anode current is reduced to zero
Gate voltage is reduced to zero
Gate is reverse biased
None of the above
If the gate voltage of an SCR is removed, then the
anode current decreases
anode current does not decrease at all
anode current increases
cathode current increases
An SCR combines the features of …………..
A rectifier and resistance
A rectifier and transistor
A rectifier and capacitor
None of the above
What is application of satellite systems?
None of the above
Whether forecasting
Terrestrial communication
point to point communication