Best Interview Questions & Answers for Triac, DIAC and UJT

In this tutorial, we are going to learn about the top Interview Questions & Answers for Triac,DIAC and UJT.

Question 1. How many terminals in Triac?

Answer – A triac has three terminal terminals device is main terminal 1 (MT1), main terminal 2 (MT2), and gate terminal G.

Question 2. Can use Triac as a bidirectional switch?

Answer – Yes can use as a bidirectional switch.

Question 3. How many terminals of Diac?

Answer – A Diac has two terminals which are T1 & T2. Diac can not use as a control and amplification but it can use as a bidirectional switch.

Question 4. How many layers of Triac?

Answer – Triac has four layers which are PNPN and NPNP. When it is in positive direction then it will be PNPN and when it is in negative direction then it will be NPNP.

Question 5. How many PN junction of Diac?

Answer – A Diac has two PN junctions. Diac always work in forward bias and reverse bias same as diode.

Question 6. Is Dias has Gate terminal device?

Answer – Diac has not gate terminal. But TRIAC, FET and UJT has Gate terminal.

Question 7. How many layers of Diac?

Answer – A Diac has three semiconductor layers which are basically combination of NPN and PNP.

Question 8. How many PN junction of UJT?

Answer – A UJT has only PN junction it can be P or N and three terminals device The UJT has three terminals which is Emitter (E) and two Bases (B1 and B2).

Question 9. What is use of UJT?

Answer – A sawtooth generator, Like that used  in free-running oscillators and pulse generation circuits at few hundred kilohertz frequency.

Question 10. If have high current load then how can we use SCR in circuit?

Answer – If have high load current in circuit then can use Parallel connection of SCR in circuit.

Question 11. What is the combination of latching latching current and holding current of SCR?

Answer – Generally latching current is 2 or 3 times of holding current. Suppose that holding current is 20mA then latching current should be more than 50mA.

Question 12. What is effect of gate current at anode current if the SCR is ON?

Answer – When the SCR is ON, Then Gate current will no effect on the anode current.

Question 13. How can we protect SCR from thermal conditions?

Answer – By using heat sink, Excess amount of heat can be dissipated quickly by mounting the SCR on a heat sink.

Question 14. How can use SCR as a controlled device?

Answer – By applying gate pulse the SCR can be turned ON during forward blocking mode. While SCR cannot be turned OFF by applying gate pulse. It automatically turns off when anode current is below the holding current.

Question 15. What is full form of SCR?

Answer – SRC full form is Silicon Controlled Rectifier.

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