Try five free Mississippi electrical practice questions with answers and 2020 NEC references. This 2020 NEC set practices trade topics for Mississippi’s Master and Residential Electrician exams. A qualifying party’s exam result supports the company’s license application; it does not replace the application or Law and Business exam. Work with your code book open, record your answers, then open the explanations below.
Start with the Mississippi exam guide for the official bulletin, approved books, exam format and registration steps.
Taking the Master or Residential exam? PSI grades both on the 2020 NEC, and that's the edition JCR's Mississippi package teaches. $495 buys 100 video lessons (21 hours), a 152-page JCR workbook with a six-week plan, 500+ mock exam questions in print and online, and a set of permanent NEC tabs.
Which Mississippi exam are you preparing for?
| Quick facts | Mississippi electrical exams |
|---|---|
| Test company | PSI, at its Jackson test center or other PSI centers. Rules are in the PSI Mississippi contractor bulletin (April 23, 2026). |
| Master Electrician | 80 questions, 3 hours, 70% to pass, $120, 2020 NEC |
| Residential Electrician | 60 questions, 3 hours, 70% to pass, $120, 2020 NEC |
| Law and Business Management | 50 questions, 2 hours, 70% to pass, $120. Required for every applicant. |
| NASCLA option | 100 questions, 270 minutes, 75% to pass. It can replace the Master Electrician exam. |
| Before you book | MSBOC approves your company's application first. The fee is $400 for a commercial license or $50 for residential (MSBOC license page). |
Prepare separately for Mississippi Law and Business. Use the Master or Residential trade outline that matches your application.
Mississippi electrical practice test: 5 questions
Use 15 minutes as a practice target. This is a short NEC lookup drill, not a full-length exam or a prediction of your score. Questions are selected from JCR’s practice bank and may also appear in other JCR state guides.
Question 1: Services
Overhead 120/240-volt service conductors cross a residential driveway. What is the minimum clearance above final grade?
- 10 feet
- 12 feet
- 15 feet
- 18 feet
Question 2: Motors
A 10 hp, 230-volt, single-phase motor runs in continuous duty. What is the minimum ampacity for its branch-circuit conductors?
- 50 amps
- 57.5 amps
- 62.5 amps
- 68.75 amps
Question 3: Grounding electrodes
A dwelling service uses two ground rods because one rod alone doesn't meet the code. What is the minimum distance between the rods?
- 4 feet
- 6 feet
- 8 feet
- 10 feet
Question 4: Conduit fill
Five individual conductors are installed in a complete conduit run longer than 24 inches. No special fill allowance applies. What is the most of the conduit's cross-section they may fill?
- 31 percent
- 40 percent
- 53 percent
- 60 percent
Question 5: Appliances
A 50-gallon storage water heater is rated 4,500 watts at 240 volts. What is the minimum ampacity for its branch-circuit conductors?
- 18.75 amps
- 20 amps
- 23.44 amps
- 28.13 amps
Answer key with 2020 NEC sections
Finish all five before opening the answers. Give yourself one point for each correct choice, then look up every missed section.
Show the answer to question 1Hide the answer to question 1
1. B, 12 feet (NEC 230.24(B)(2))
Overhead service conductors need 12 feet over residential property and driveways when the voltage is 300 volts or less to ground. A 120/240-volt service is 120 volts to ground. Over public streets, alleys and parking areas with truck traffic, it's 18 feet.
Show the answer to question 2Hide the answer to question 2
2. C, 62.5 amps (NEC Table 430.248 and 430.22)
Use the table current, not the nameplate. Table 430.248 lists 50 amps for a 10 hp, 230-volt single-phase motor. Section 430.22 requires 125% of that: 50 × 1.25 = 62.5 amps. The 57.5-amp choice is the table value for a 200-volt motor.
Show the answer to question 3Hide the answer to question 3
3. B, 6 feet (NEC 250.53(A)(3))
When more than one rod, pipe or plate electrode is used, they must be at least 6 feet apart. A single rod needs a supplemental electrode unless it has 25 ohms or less resistance to earth (250.53(A)(2)).
Show the answer to question 4Hide the answer to question 4
4. B, 40 percent (NEC Chapter 9, Table 1)
Over 2 conductors may fill 40% of the conduit. One conductor may fill 53%, and two may fill 31%. See a full conduit fill example.
Show the answer to question 5Hide the answer to question 5
5. C, 23.44 amps (NEC 422.13)
The heater draws 4,500 ÷ 240 = 18.75 amps. Storage water heaters of 120 gallons or less get branch-circuit conductors and overcurrent protection sized at no less than 125% of their rating: 18.75 × 1.25 = 23.44 amps.
How to study after this practice test
- Log the lookup. Write down the article, section or table you used and how long it took to find.
- Work the calculation again. Keep the units and intermediate steps so you can find an arithmetic error.
- Use your exam’s edition. A newer installation code is not automatically the edition used for your license test.
- Cover the full outline. Prepare separately for Mississippi Law and Business. Use the Master or Residential trade outline that matches your application.
Mississippi electrical practice test FAQ
Are these actual licensing exam questions?
No. These are JCR practice questions selected to help you study NEC rules. They are not supplied or endorsed by the exam vendor or licensing board.
Does getting all five right mean I am ready?
Five questions are too small a sample to judge readiness. Use a full practice exam, review the official content outline and practice every required subject.
Which NEC edition does this practice test use?
This set uses the 2020 NEC. This 2020 NEC set practices trade topics for Mississippi’s Master and Residential Electrician exams. A qualifying party’s exam result supports the company’s license application; it does not replace the application or Law and Business exam.
Keep practicing for your Mississippi exam
Use the course links above for the exam and edition you are taking. Review the complete Mississippi exam guide before you order.
Try JCR’s free NEC practice app. Check the edition shown in the app before using its questions for your exam.
More Mississippi guides
Sources and answer references
- PSI Mississippi Contractor Examinations bulletin (updated 4/23/2026)
- PSI: Mississippi contractor exams
- MSBOC: testing
- MSBOC: FAQ
- MSBOC: license applications
- MSBOC: classifications
- City of Tupelo contractor's application
- NFPA 70, 2020 edition: see the section citations in each answer.
- JCR maryland electrical practice test: source practice-bank questions.
- JCR washington electrical practice test: source practice-bank questions.
Reviewed October 22, 2026. NEC answers and section references checked against the stated edition in NFPA LiNK. Exam information follows the linked official bulletins. Questions are selected from JCR’s shared practice bank, with clarifications where needed.