T4Tutorials .PK

Chapter 6 THYRISTORS MCQs

1. .2 The four-layer devices with a control mechanism are commonly referred to as.

(A) Thyristors


(B) Transistors


(C) Diodes


(D) None of the above




2. .3 Which of the following is a latching device?

(A) BJT


(B) JFET


(C) MOSFET


(D) SCR




3. .4 An SCR has PN junctions.

(A) Two


(B) Three


(C) Four


(D) None of the above




4. .5 An SCR has semiconductor layers.

(A) Two


(B) Three


(C) Four


(D) None of the above




5. .6 An SCR has three terminals

(A) Cathode, anode, gate


(B) Cathode, anode, grid


(C) Anode, cathode, drain


(D) None of the above




6. .7 An SCR behaves as a switch.

(A) Unidirectional


(B) Bidirectional


(C) Mechanical


(D) None of the above




7. .8 An SCR is sometimes called

(A) Triac


(B) Diac


(C) Unijunction transistor


(D) Thyristor




8. .9 An SCR is made up of

(A) Germanium


(B) Silicon


(C) Carbon


(D) None of the above




9. .10 In the normal operation of an SCR, anode is………w.r.t. cathode.

(A) At zero potential


(B) Negative


(C) Positive


(D) None of the above




10. .11 In the normal operation of an SCR, gate is………w.r.t. cathode.

(A) Positive


(B) Negative


(C) At zero potential


(D) None of the above




11. .12 The control terminal in an SCR is

(A) Cathode


(B) Anode


(C) Anode supply


(D) Gate




12. .13 The normal way to turn ON an SCR is by

(A) Breakover voltage


(B) Appropriate anode current


(C) Appropriate gate current


(D) None of the above




13. .14 An SCR is turned OFF by

(A) Reducing anode voltage to zero


(B) Reducing gate voltage to zero


(C) Reverse biasing the gate


(D) None of the above




14. .15 An SCR is a trigger device.

(A) Voltage


(B) Current


(C) Voltage as well as current


(D) None of the above




15. .16 When an SCR is turned ON, the voltage across it is about

(A) Zero


(B) 10 V


(C) 0.1 V


(D) 1 V




16. .17 In an SCR circuit, the angle of conduction can be changed by

(A) Changing anode voltage


(B) Changing gate voltage


(C) Reverse biasing the gate


(D) None of the above




17. .18 If firing angle in an SCR circuit is increased, the output

(A) Remains the same


(B) Is increased


(C) Is decreased


(D) None of the above




18. .19 If the gate current is increased, then anode-cathode voltage at which SCR starts conduction

(A) Is decreased


(B) Is increased


(C) Remains the same


(D) None of the above




19. .20 A Diac has terminals.

(A) Two


(B) Three


(C) Four


(D) Five




20. .21 A Device which does not have a gate terminal is.

(A) TRIAC


(B) SCR


(C) FET


(D) DIAC




21. .22 A normal way to turn on a Diac is by.

(A) Gate Current


(B) Gate Voltage


(C) Break-over Voltage


(D) None of the above




22. .23 Which of the following can be triggered in either direction?

(A) SCR


(B) Shockley Diode


(C) DIAC


(D) SCS




23. .24 A Triac is equivalent to two SCRs in.

(A) Parallel


(B) Series


(C) Inverse-Parallel


(D) None of the above




24. .25 A Triac is a switch.

(A) Bidirectional


(B) Unidirectional


(C) Mechanical


(D) None of the above




Exit mobile version