DIY Quiz: Vol. 3 Answers
What’s your level of expertise?
1. True or False? It’s safe to put a 100-watt-equivalent compact fluorescent or LED bulb in a fixture rated for 60 watts.
True. Compact fluorescent and LED bulbs are more efficient than incandescent bulbs and require less energy to produce an equivalent amount of light. They also give off less heat. That’s why you can safely install a 100-watt-equivalent fluorescent or LED bulb in a fixture rated for a maximum of 60 watts.
2.What is this piece of hardware used for?
A. Punching a hole in a plumbing pipe.
B. Connecting a ground wire to a copper stake.
C. Installing a crimping wire connector.
D. Cracking a rusty nut.
(D) The tool shown is a nut splitter. It’s used to remove nuts that are too corroded to turn with a wrench. You place the tool over the nut, aligning the chisel-shaped end of the breaker with a flat spot on the frozen nut. Turning the splitter bolt with a wrench forces the chisel into the corroded nut and eventually cracks it, allowing the nut to be removed without damaging the bolt it’s threaded to.
3. Your car starter clicks but won’t start the car when you turn the key. Which of the following should you try before calling for help?
A. Shake the battery to mix up the acid inside.
B. Bang the battery terminals with your shoe.
C. Turn on the car lights.
D. Rap the starter motor with a tire iron.
(B & D) Rotating the battery cable connector slightly by banging it with your shoe could reestablish a corroded connection. If it works, be sure to remove the cables and clean the connections when you get back to your garage. Also, rapping on the starter motor with a tire iron can jar loose a stuck electrical contact.
4. How can you tell when it’s time to replace a serpentine belt?
A. The belt has started to slip.
B. When you test the belt with a belt wear gauge, the gauge sits flush with the top of the ribs.
C. The belt has stretched and turned gray.
D. A belt tension gauge shows increased brittleness.
(B) When you test your serpentine belt with a belt wear gauge, lay the gauge in the ribs on the belt and run your fingers across them. If the gauge sits flush with the top of the ribs, the belt is worn out.
5.What is the name of the plumbing part shown with the arrow pointing to it?
A. ABS trap adapter
B. AAV (air admittance valve)
C. PVC hub connector
D. OAV (open air vent)
(B) Plumbing codes require drainpipes from plumbing fixtures to be connected to a vent pipe within a specified distance from the fixture trap. Vent pipes typically exit through the roof of your house and allow air to enter the drainpipe as the water is leaving, preventing a vacuum or siphoning effect that could pull water out of the fixture trap. In situations where it’s difficult to connect to a vent pipe, some jurisdictions permit the use of an air admittance valve (AAV) to satisfy the venting requirement. The AAV is a one-way valve that allows air to enter the pipe but doesn’t allow potentially hazardous sewer gas to leave.
6. True or False? You shouldn’t install a receptacle rated for 15 amps on a 20-amp circuit.
False. The National Electrical Code allows 15-amp-rated receptacles to be installed on 20-amp circuits in some cases. The requirements for using a 20-amp-rated receptacle are too complex to summarize here. Check with your electrical inspector before installing receptacles to make sure you use the correct one.
7. In most jurisdictions, how deep must you bury underground feeder cable that is protected by a GFCI?
A. 6 in.
B. 12 in.
C. 18 in.
D. 24 in.
(B) According to the National Electrical Code, direct-bury underground feeder (UF) cable can be buried as shallow as 12 in. if it’s protected by a ground fault circuit interrupter (GFCI) and the portion of the cable that runs from the house to 12 in. below ground is inside a PVC conduit (see photo). Unprotected UF cable must be buried at least 24 in. deep.
8. Experts recommend installing a bath fan that can provide a complete air change about eight times per hour. The cfm rating on fans tells you how many cubic feet per minute the fan will exhaust. If your bathroom is 8 ft. wide, 10 ft. long and has an 8-ft. ceiling, what is the closest size fan that would provide the recommended amount of ventilation?
A. 60 cfm
B. 100 cfm
C. 150 cfm
D. 200 cfm
(B) To calculate the answer, first find the volume of the bathroom in cubic feet by multiplying the width (8 ft.) by the length (10 ft.) by the height (8 ft.), which in this case equals 640 cu. ft. This volume of air must be replaced eight times in an hour, so multiply 640 by 8 to get 5,120 cu. ft., the total volume of air replaced in an hour. To get the cubic feet per minute, divide by 60 (the number of minutes in an hour), which equals 85.33. You’d need a fan that moves at least 85 cu. ft. per minute, so the closest answer is (B) 100 cfm.
9. True or False? It’s safe to drive on tires when the depth gauge shows 1/16 in. of tread remaining.
False. Tests conducted by consumer testing organizations show that tires with 1/16-in. tread required twice the stopping distance as tires with 1/8 in. And if you see cracks in the tread or sidewalls, you should replace your tires regardless of the tread depth.
10.Which of the following describes the chain in the photo at left?
A. The tension is correct.
B. The chain is too tight.
C. The chain is too loose.
D. The chain is too long.
(C) The chain is too loose. The tension is correct when you can’t lift the chain drivers free of the bar groove, but you can still drag the chain easily around the bar with a gloved hand.