ELECS 3 Quiz 1-4 Review PDF

When the Ve increase the resistance value in Rb1 \_\_\_\_\_\_\_\_\_\_\_. DECREASE 2. When positive voltage is applied to the emitter the PN junction is \_\_\_\_\_\_\_\_\_. FORWARD BIAS 3. In negative resistance region, an increase in IE causes a \_\_\_\_\_\_\_\_ in Ve. DECREASE 4. U...

When the Ve increase the resistance value in Rb1 \_\_\_\_\_\_\_\_\_\_\_. DECREASE 2. When positive voltage is applied to the emitter the PN junction is \_\_\_\_\_\_\_\_\_. FORWARD BIAS 3. In negative resistance region, an increase in IE causes a \_\_\_\_\_\_\_\_ in Ve. DECREASE 4. UJT structure forms how many PN junction? ONE 5.Rb1 is always \_\_\_\_ than Rb2 and is also a variable resistance because it depends on the bias voltage. GREATER 6\. Where is the gate of the PUT located? 7\. How many layers does a PUT have? 8.Explain the difference between a PUT and a UJT. QUIZ 1. What is the standard form of TRIAC? Ans.: Triode for Alternating Current 2. The current rating of triode for alternating current is up to \_\_\_\_\_\_\_\_\_\_\_\_? Ans.:25 amperes 3. The TRIAC is a two way \_\_\_\_\_\_\_\_\_\_\_\_\_\_ with one gate terminal? Ans.: SCR 4. The most common break over voltage for diacs is\_\_\_\_\_\_\_\_\_. Answer: 32V 5. This circuit utilizes a resistor ® and a capacitor © connected to the gate terminal of the TRIAC. Answer: RC Gate Control Circuit 6. This device is a type of voltage-sensitive component, such as a Diac, that is often used in Conjunction with a TRIAC to ensure reliable triggering. Answer: Breakover Devices. 7-9. For 3 points, What are the four possible triggering modes of a triac? 1. Positive main terminal voltage, positive gate current 2. Positive main terminal voltage, negative gate current 3. Negative main terminal voltage, negative gate current 4. Negative main terminal voltage, positive Gate current 10\. What device is used to prevent transient surges in triacs? Answer: RC. 11\. What type of voltage rise can trigger a triac accidentally? Answer: dv/dt. 12.What component is essential in industrial AC lines for reliable triac operation? Answer: Suppression. True or False: A UJT trigger circuit with voltage feedback provides a more precise and stable trigger voltage Compared to a resistive feedback circuit. Answer: True The frequency of oscillation in a UJT relaxation oscillator is inversely proportional to the time Constant of the RC charging network. Answer: True A UJT can be used as a simple relaxation oscillator to generate a square wave output. Answer: False (It generates a sawtooth waveform.) Quiz: Optoelectronics devices and sensor 1. When the light (photons) hits the metal surface it ejected electrons and that electrons are called? Ans: Photoelectron. 2. This refers to a minimum amount of energy needed to remove an electron from a metal surface. Ans: work function 3. It is a process by which a material captures light energy and converts it into other forms of energy, usually heat. Ans: Light Absorption 4. VB and CB stand for? Ans: Velence Band (VB) Conduction Band (CB) 5. It is an energy level within the material that can trap electrons. Ans: Confined State 6. What is the c value that is used as a good approximation. Ans: c= 3 108 m/s 7. What is the value of Planck's constant Ans: 6.62×10−34 8-10. Three main types of optical amplifier. Ans: EDFAs (erbium-doped fiber amplifiers) SOAs (semiconductor optical amplifiers) Fiber Raman amplifiers 11-12. Where does solar cell applicables? Gave me two examples Ans. Rural electrification, telecommunication systems, ocean navigation aids, electric power generation system in space and remote monitoring and control systems. 13-15. Draw the schematic diagram of the given diodes.... LED LD'S PHOTODIODE GROUP 4 INDUSTRIAL AUTOMATIC WELDING SYSTEM CONTROL QUIZ \_\_\_\_\_\_\_\_ flows down the electrode power that leads to the electrodes and through the metal-to-metal contact between wheel rim and spider, thereby creating the weld. Answer: Current It is turned on and off in short bursts. Answer: Pulsation What block of the sequence control circuit has the job of receiving the information that an interval is complete from the interval time counter? Answer: Block B It is the block in the sequence control circuit where the heat-cool counter is identical in concept to the interval time counter. It counts backwards from the preset number down to zero, making one backward count for each cycle of the ac line. Answer: Block H During this interval, the Engage Electrodes Solenoid activates, extending the electrodes to contact the wheel and spider. Answer: Squeeze Interval At what pulse does the FFA toggles OFF, and the combination of FFA and FFB being ON allows FFC to toggle ON? Answer: Fourth Pulse It is an interval in the Decoder wherein the unique condition C = 1 is shown. Answer: Release Interval What device or system is used to precisely control and measure the timing of various phases in the welding process? Answer: Interval Time Counter 9-11. Give at least three functions of interval time counter. Answer: Timing Control Process Consistency Productivity Analysis Heat Management Note: The Interval Time Counter has four functions, but we only require three answers. This can be written in any order. 12-15. Essay Question: In the real world power circuits, why is there a need for 2 pairs of SCR-ignitron per phase? Answer: 2 pairs of SCR-ignitron allows the direction of welding current to reverse from one current pulsation to the next. This prevents saturation of the welding transformer core.