Look at the four schematic symbols shown All four of these d

Look at the four schematic symbols shown. All four of these devices conduct current in only one direction. are used as replacements for relays. exhibit negative resistance. are designed to operate in AC circuits only. All of the components in the figure are operating currently, and Bulb B1 is off. Which of the following actions must you take to make Bulb B1 light up? Press and hold switch S1. Momentarily press switch S1. Momentarily press switch S2 to de-energize RL1. Momentarily press switch S2 to energize RL1. Two electronics technicians are discussing the wire resistance table shown. Technician A says that the resistance of a 300-foot section of wire with a cross-sectional area of 642.40 circular mills will have a resistance of 16.46 ohms. Technician B says that a 500-foot section of wire with a cross-sectional area of 642.40 circular mills will have a resistance of 8.2 ohms. Which of the following statements is correct? Only Technician B is correct. Only Technician A is correct. Neither of the two technicians is correct. Both of the technicians are correct. Two electronic technicians are looking at the four schematic symbols shown. Technician A says that Symbol 1 is the symbol for a tunnel diode, and that symbol 4 is the symbol for a TRIAC. Technician B says that Symbol 2 is the symbol for a UJT, and that Symbol 3 is the symbol for an SCR. Which of the following statements is correct? Both of the technicians are correct. Only Technician A is correct. Only Technician B is correct. Neither of the two technicians is correct. Two electronics technicians are comparing the advantages and disadvantages of analog and digital multimeters. Technician A says that an analog meter has greater accuracy and stability than a digital meter. Technician B says that an analog meter can track a varying signal better than a digital meter. Which of the following statements is correct? Only Technician B is correct. Both of the technicians are correct. Neither of the two technicians is correct. Only Technician A is correct.

Solution

16. Option B

Explanation: All the three devices except TRIAC are unidirectional. Similarly only UJT and tunnel diode device will experience negative resistance. But all the devices can be used in either AC or DC circuit and as switch as well.

17. Option B

18. Question is not readable as the words in image is not clear.

19. Option A

Explanation: Symbol -1 = Tunnel diode, Symbol-2 = UJT, Symbol-3 = SCR and Symbol-4 = TRIAC

20. Option D

Explanation: Analog meters are accurate as the values in digital meter fluctuate but many errors happen while using analog meters and continuous calibration is required for analog meters hence stability is more in analog meters compared to digital meters. But both the meters can track varrying signal equally precisely.