CSLB C-10 Electrical Exam Prep (Latest 2026/ 2027 Update) | 100% Verified Questions & Answers | Grade A

CSLB C-10 Electrical Exam Prep (Latest 2026/ 2027 Update) | 100% Verified Questions & Answers | Grade A QUESTION In an electrical system, what is the white wire? 1. hot 2. neutral 3. ground 4. jumper Answer: B. The white wire is the "neutral" wire, it takes any unused electricity and current and sends it back to the breaker panel. QUESTION What is printed on the label of underground direct-burial wire? 1. UG 2. LL 3. UF 4. UL Answer: C. Reference 2022 CEC 340.6 Listing Requirements. Type UF cable and associated fittings shall be listed. QUESTION When outdoor rated fiber cable enters a building, it should be spliced to an indoor-type fiber cable within ________ from the cable entrance. 1. 25 feet 2. 30 feet 3. 40 feet 4. 50 feet Answer: D. QUESTION Which of the following must be posted at all job sites? 1. Earthquake Preparedness 2. First Aid Kit 3. Fire Escape Route Map 4. All of these Answer: B. Reference the California Code of Regulations, Title 8, Section 1512(c) First-Aid Kit. (1) Every employer working on or furnishing personnel on a construction project, on line crews and on other short duration or transient jobs shall provide at least one first-aid kit in a weatherproof container. The contents of the first-aid kit shall be inspected regularly to ensure that the expended items are promptly replaced. The contents of the first-aid kit shall be arranged to be quickly found and remain sanitary. First-aid dressings shall be sterile in individually sealed packages for each item. QUESTION What is the purpose of AFCIs? 1. to protect against electric shocks 2. to protect against power outages 3. to protect against fires 4. to protect against metal thieves Answer: C. AFCI stands for Arc-Fault Circuit Interrupter. They are similar to GFCIs but they protect against house fires caused by arcing. Arcing can be caused by many things, including deterioration of old wiring, damage to wiring caused by nails or staples, damaged cords of cord-and-plug connected equipment (lamps, alarm clocks, etc.), or having furniture pushed up against an outlet and dislodging a plug. It is possible for an arc to start a fire either in the furnishings of the room or inside the wall cavity. The AFCI is intended to sense the arcing and de-energize the circuit. It is acknowledged that AFCIs cannot prevent all electrical fires since the device will not trip until after arcing has been sensed and the first arc may ignite a fire. The risk of fire is greatly reduced, however, because the AFCI will prevent subsequent arcing in the cases where the first arc does NOT ignite a fire. QUESTION An IC contains: 1. Diodes 2. Resistors 3. Transistors 4. all of these Answer: D. An integrated circuit (IC), sometimes called a chip, microchip or microelectronic circuit, is a semiconductor wafer on which thousands or millions of tiny resistors, capacitors, diodes and transistors are fabricated. QUESTION The "555" IC is a? 1. Amplifier circuit 2. AND circuit 3. Timer circuit 4. Power supply circuit Answer: C. Answer "C" is correct. The 555 timer IC is an integrated circuit used in a variety of timer, delay, pulse generation, and oscillator applications. QUESTION How many wires would you run from the controller, if you have a six- station Sprinkler station? 1. 8 2. 7 3. 9 4. 6 Answer: B. 6 + 1 common. You have the 6 controller wires and the one common wire which is the ground wire. QUESTION Exterior connectors used on conduit are: 1. waterproof 2. water-resistant 3. either water-resistant or waterproof 4. galvanized Answer: C. Connectors suitable for outside installations are not all waterproof. Connectors are selected based on their UL listing for a specific purpose. Outside connectors should be at least raintight, but if the installation is below grade or subject to immersion, this is not enough. Plastic or aluminum connectors are not galvanized. QUESTION What type must low-voltage control conductors be? 1. LL 2. UF 3. UG 4. UL Answer: B. UF conductors are underground feeder cables that are used in a variety of applications, including: Irrigation: UF cables are used in the irrigation industry to provide power to submersible pumps and irrigation systems. They can be buried directly underground or used in a raceway. Sheds: UF cables are often used to run electricity to a sub-panel in a shed. Interior wiring: UF-B cables can be used for interior branch circuit wiring in residential or agricultural buildings. QUESTION The thermostat for a H.V.A.C. system, should be mounted how many feet from the floor? 1. 6 feet 2. 5 feet 3. 4 feet 4. 3 feet Answer: C. 2019 California Energy Code lists following the thermostat manufacturer's recommendation per 2019 California Energy Code, section 110.2; and 2019 California Accessibility Code lists 48 inches per 1136A.2. QUESTION A transistor can work as (a)an: 1. Switch 2. Inverter 3. Amplifier 4. all of these Answer: D. The transistor will operate as an amplifier or other linear circuit if the transistor is biased into the linear region. The transistor can be used as a switch if biased in the saturation and cut-off regions. A transistor work like an inverter such as producing a high signal (logic 1) at the output when the applied input is low, and it can produce a low signal (logic 0) at the output when the applied input is high. QUESTION The voltage in a low-voltage garden lights is? 1. 6V 2. 12V 3. 24V 4. 36V Answer: B. Low voltage(12 volts) landscape lighting is the most common option for residential outdoor lighting. QUESTION What is the minimum number of small appliance circuits to supply a kitchen? 1. 1 2. 2 3. 3 4. 4 Answer: B. The Electrical Code requires at least two small-appliance branch circuits to supply a residential kitchen. The actual number of circuits for a specific installation will depend upon the load calculations, but there should never be less than two. This does not include branch circuits for large appliances (i.e; oven). QUESTION When installing cable and raceways parallel to framing members and furring strips, the cable or raceway shall be installed and supported so that the nearest outside surface of the cable or raceway is not less than _______ from the nearest edge of the framing member or furring strips where nails or screws are likely to penetrate. 1. 3/4″ 2. 1″ 3. 1 1/4″ 4. 1 1/2″ Answer: C. CEC 300.4 (A) states that answer "C" of 1 ¼ would be the correct answer.