DIAC Question & Answers November 8, 2022 By WatElectronics This article lists 50 DIAC MCQs for engineering students. All the DIAC Questions & Answers given below include a hint and a link wherever possible to the relevant topic. This is helpful for users who are preparing for their exams, interviews, or professionals who would like to brush up on the fundamentals of DIAC. When power is applied to load it must be regulated. Electrical methods used in controlling fan or motor speed don't provide proper control for the system when power has flowed. An extensive amount of power is wasted in such situations. In present scenarios, various devices are developed to allow the power flow in control of the larger blocks present in the system. The instrument utilized for such purposes are referred to as Controlled switches and offer control rectification, power inversion, and regulation in loads. Semiconductor devices that offer to switch are SCR, UJT, TRIACs, and DIACs. Understanding switching devices is more manageable when knowing thyristors. Thyristors can supply half of the power. Two thyristors are combined forms TRIAC. DIACs are switching and bi-directional devices. A Gate terminal is absent in such devices. Both polarities can switch ON DIACs making it bi-directional. Two Zener diodes are connected to form DIAC and can utilize to trigger TRIACs. Switching lights, Fluorescent lamps, and dimming applications use DIACs. 1). What does DIAC stand for? Digital to Analog Converter Diode for Alternating Current Digital Input Analog Comparator Dynamic Input Analog Current Hint 2). Diode conducting after the Breakover voltage is referred to as _____________? Zener Diode DIAC TRIAC Schottky Diode Hint 3). DIAC is a _________________? Bidirectional Switch Full Wave Switch Unidirectional Switch a & b Hint 4). How many diodes are depicted in the DIACs symbol? Four Three Two One Hint 5). How many terminals do a DIAC consist of? Four Three Two One Hint 6). ____________ are referred to as Symmetrical Trigger Diodes? Zener Diode DIAC TRIAC Schottky Diode Hint 7). Which of the following voltage in DIAC is based on factors of fabrication? Forward Voltage Reverse Voltage Breakdown Voltage In Built Voltage Hint 8). Breakdown voltage occurred in DIAC leads to ____________? Increased Resistance Decreased Resistance Increase Power Decrease in Power Hint 9). Decrease in resistance of DIAC leads to decrease in ___________? Current Voltage Temperature Pressure Hint 10). DIAC remains in a state of conduction until the flow of current gets dropped to certain values referred to as ______________? Reverse Current Forward Current Holding Current Static Current Hint 11). If the current in DIAC is lower than the holding currents switch it to __________________? High Resistance State Low Resistance State Conducting State b & c Hint 12). DIAC behaves _____________ in both directions? Different Distinct Equal Can’t Say Hint 13). How many layers does a DIAC have? Four Three Two One Hint 14). Which material does DIAC have on both sides? P-type Material N-type Material PN Material PNP Material Hint 15). What are the terminals of DIAC? Anode Cathode Source a & b Hint 16). How many junctions does DIAC consist of? Four Three Two One Hint 17). Diodes in DIAC are ______________? Forward Biased Reverse Biased Partially Biased a & b Hint 18). Why is DIAC considered to be Bi-directional? Current Flow Direction is not Specified Voltage Flow Direction is not Specified Current Flow Direction is Specified Voltage Flow Direction is Specified Hint 19). What material was utilized in the construction of DIAC? P-type Materials N-type Materials Insulators a & b Hint 20). Decrease in voltage leads to an increase in the flow of the current of DIAC referred to as ____________ region? Positive Static Resistance Region Negative Dynamic Resistance Region Positive Dynamic Resistance Region Negative Static Resistance Region Hint 21). What happens if the current in DIAC decreased below the Holding current? DIAC Enter Non-Conduction State DIAC Enter Conduction State DIAC Resistance Decrease a & c Hint 22). Three regions in DIAC are doped in _____________? Same Levels Different Levels Distinct Levels Either Same or Distinct Hint 23). How do the characteristics of DIAC resemble? Letter A Letter B Letter V Letter Z Hint 24). DIACs are constructed using ______________? Three Layers Four Layers Five Layers a & c Hint 25). Which layer DIAC is used widely? Three Layers Four Layers Five Layers a & c Hint DIAC MCQs for Exams 26). _____________ DIAC have 30 Volts of Breakover voltage? Three Layers Four Layers Five Layers a & c Hint 27). Five layers of DIAC resemble the combo of _____________? Two SCRs Two Zener Diodes Two Thermistors Two TRIACs Hint 28). In what quadrants of the characteristics curve DIAC operates? First Second Fourth Fifth Hint 29). ______________ is equal to four layers pair of SCRs? Zener Diode DIAC TRIAC Schottky Diode Hint 30). What is used in Solid-state Triggering? Zener Diode DIAC TRIAC Schottky Diode Hint 31). DIAC operating with a voltage of DC around it behaves like _________________? Zener Diode SCR TRIAC Schockley Diode Hint 32). What type of element is DIAC? Active Passive Static Dynamic Hint 33). What kind of switching DIACs offer? Asymmetrical Switching Symmetrical Switching Anti-symmetrical Switching Dynamic Switching Hint 34). NTE6408 is the example of ______________? DIAC TRIAC SCR LASER Diode Hint 35). DIACS are ____________? Bi-directional Controlled Uncontrolled a & c Hint DIAC MCQs for Students 36). DIACs are constructed in _________ form? PNP NPN Either PNP or NPN None Hint 37). DIAC can conduct if the voltage applied increases ____________? Above 30 V Below 20 V Above 20 V Below 30 V Hint 38). High voltages are blocked in ______________? Zener Diode DIAC TRIAC Schottky Diode Hint 39). Why DIAC is referred to as an Uncontrolled Switch? Present Gate Terminal Absent Gate Terminal Present Source Terminal Present Drain Terminal Hint 40). What used in regulating the power supply provided to loads of AC? Zener Diode DIAC TRIAC a & b Hint 41). How DIACs can be turned ON or OFF? Reducing Current Level Reducing Voltage Level Reducing Temperature Level Reducing Power Level Hint 42). Amplification or control is not offered by _______? Zener Diode DIAC TRIAC Schottky Diode Hint 43). SIDAC have __________? High Breakover Voltage Handle High Currents Low Breakover Voltage a & b Hint 44). To trigger TRIAC internally, what does a Quadrac consist ? Zener Diode DIAC SCRs Schottky Diode Hint 45). How DIAC is connected to TRIAC to trigger it? Series Parallel a & b None Hint 46). Transistors without the base referred to as _______________? Zener Diode DIAC TRIAC Schottky Diode Hint 47). Combination of DIAC and TRIAC used in ____________? Zener Diode Quadrac SCR Schottky Diode Hint 48). Fluorescent lamps with Starter circuits use ___________? Zener Diode DIAC TRIAC Schottky Diode Hint 49). Light dimmers use ____________? Zener Diode DIAC SCR Schottky Diode Hint 50). __________ doesn’t have any trigger or gate electrode? Zener Diode DIAC SCR Schottky Diode Hint For More MCQs TRIAC Question & Answers Please fill in the comment box below. Time is Up! Time's up
