DIAC are specifically designed to trigger______________?

Related Mcqs:

1. As the breakdown voltage reached, the DIAC exhibits?

   A. Negative resistance characteristics
   B. Goes into avalanche condition
   C. Voltage drop snaps back
   D. All of these

2. DIAC and TRIAC both are semiconductors devices and conduct in____________________?

   A. DIAC conducts in forward direction and TRIAC conducts in reverse direction
   B. Both conducts in forward direction
   C. Both conducts in reverse direction
   D. Both conducts in either direction

3. An SCR is considered to be a semi controlled device because_______?

   A. it can be turned OFF but not ON with a gate pulse.
   B. it conducts only during one half cycle of an alternating current wave.
   C. it can be turned ON but not OFF with a gate pulse.
   D. it can be turned ON only during one half cycle of an AC.

4. Which semiconductor device acts like a diode and two transistor?

   A. UJT
   B. Diac
   C. Triac
   D. SCR

5. Which one is most suitable power device for high frequency (>100 KHz) switching application?

   A. BJT
   B. Power MOSFET
   C. Schottky diode
   D. Microwave transistor

6. A string of n parallel SCRs is operated at 72 KA, the rating of each SCR is 1 KA. If derating factor of the string is 0.1. value of n will be___________?

   A. 60
   B. 70
   C. 80
   D. 90

7. In EMC signal, the source delivers maximum power to the input of transmission line when the transmission line input impedance

   A. Is equal to the source resistance
   B. Greater than the source resistance
   C. Smaller than the source resistance
   D. None of these

8. In rectifiers, load current flow is_________?

   A. Unidirectional
   B. Bidirectional
   C. Either (a) or (b)
   D. Non directional

9. In variable frequency, PWM gain

   A. Phase lead helps to increase the phase margin of the control loop
   B. Phase lag helps to increase the phase margin of the control loop
   C. Phase lead helps to decrease the phase margin of the control loop
   D. Phase lag helps to decrease the phase margin of the control loop

10. Electrical power output in a D.C. generator is equal to_____________?

    A. Electrical power developed in armature – copper losses
    B. Mechanical power input – iron and friction losses
    C. Electrical power developed in armature – iron and copper losses
    D. Mechanical power input – iron and friction losses – copper losses