C20 PRACTICE TEST|UPDATED&VERIFIED|WITH SOLUTIONS|GUARANTEED SUCCESS

What is the best way to maintain a drive belt motor setup? A. according to manufacturer's manual B. according to experience with own drive belt motor C. replace bearings every 6 months D. replace bearings every 12 months A. According to manufacturer's manual Silver solder starts to flow at or above approximately what temperature? A. 1000°F B. 1150°F C. 1350°F D. 1400°F B. 1150 F How are fuses rated? A. ohms B. watts C. amps D. kilowatts C. Amps If the side rail of a ladder is split away from the rungs, what should you do with the ladder? A. Discard B. Tie railing together with wire C. Use special reinforcement to attach D. Cut in half to make two smaller ladders A. Discard The drawing shows a heating equipment closet in a residential basement. Two ventilating grilles are shown. Which of the following statements is correct? A. neither grille is required B. only grille A is required C. only grille B is required D. both grilles are required D. Both grilles are required What would you use to remove a screw or a bolt that has worn out due to fatigue and rust? A. Jaw grip wrench B. Cold chisel C. Apply more force to the wrench D. use two wrenches, holding one stationary, while using the other to twist B. Cold chisel How high must a 12" diameter flue pipe project above a pitched roof line? A. 1 ft B. 2 ft C. 3 ft D. 4 ft B. 2 ft A difference between a gravity-type heating system and a forced-air system is that the gravity-type relies on the _____ for air distribution. C. Difference between hot and cold air In a central A/C unit that uses a large volume fan, how can you reduce the noise? A. use a silencer B. use sound dampening material to make a resilient mounting base C. use a rigid direct drive coupling D. place adjacent to the most important living areas B. use sound dampening material to make resilient mounting base How do you add moisture to a space? A. humidifier B. dehumidifier C. duct damper D. hydro couple A. Humidifer Which wire can carry the most current? A. 4 AWG B. 6 AWG C. 8 AWG D. 10 AWG A. 4 AWG Where should you locate registers for a forced warm-air system? A. along an outside wall B. along an inside wall C. high on a wall D. on the floor or low on a wall C. high on a wall Which of the following affects temperature in a room? A. radiation B. dehydration C. irradiation D. deradiation A. Radiation You have a multiple zone A/C system, and 3 rooms are temperature satisfied. One of these rooms is cooler than the other two. Which of the following dampers is open? A. all 3 rooms B. the room which is cooler C. The return register D. none of the above A. all 3 rooms What is a DDC? A. Direct Draft control B. Direct drive connection C. Direct digital control D. Digital discharge coupling C. Direct digital control What is the minimum gauge for an aluminum duct that can be used to convey contaminants? A. 18ga B. 20ga C. 22ga D. 24ga C. 22ga What happens when the motor on an air conditioning unit overloads? A. the unit shuts down B. the unit catches fire C. the unit runs on overload D. An alarm bell goes off A. the unit shuts down If a furnace is installed in the attic, the minimum access opening is: A. 24" x 24" B. 22" x 30" C. 30" x 36" D. 36" x 36" B. 22" X 30" What should you reverse if you want to reverse the motor turn direction on a 460V 3-phase motor? A. L1 and T4 B. L2 and T4 C. L1 and L2 D. you can't reverse the motor turn direction C. L1 and L2 Duct systems should be constructed according to: A. ASTM Standards B. Uniform Mechanical Code C. SMACNA Standards D. Cost B. Uniform Mechanical Code What makes the best insulator? A. lightweight material with many air pockets B. lightweight material with no air pockets C. heavy material with many air pockets D. heavy material with no air pockets A. lightweight material with many air pockets