NCEA 91173: electricity and electromagnetism (Level 2 Physics)

What NCEA 91173 assesses

NZQA says assessment is limited to a selection from the topics in the standard (version 2):

• Static electricity: a uniform electric field, electric field strength, the force on a charge in an electric field, electric potential energy, and work done on a charge moving in an electric field
• DC electricity: parallel circuits with resistive components in series with the source, circuit diagrams, voltage, current, resistance, energy and power
• Electromagnetism: the force on a conductor carrying a current in a magnetic field, the force on charged particles moving in a magnetic field, and the induced voltage across a straight conductor moving in a uniform magnetic field

The three grades are about how you write, not just what you know. Achieved means writing statements that show an awareness of how simple facets of phenomena, concepts or principles relate to a described situation. Merit (in-depth understanding) means writing statements that give reasons why they relate, and for mathematical solutions the information may not be directly usable or immediately obvious. Excellence (comprehensive understanding) means writing statements that show the connections between concepts.

The NCEA 91173 exam in 2026 and 2027

NCEA 91173 is one of three Level 2 Physics externals, with 91170 (waves) and 91171 (mechanics). The 2026 exam is on Wednesday 18 November, in the afternoon session. NZQA's specifications for both years say the exam is on printed paper and 91173 is a 6-credit external. In 2025 its three questions covered electric fields, simple circuits and magnetic fields.

• Equipment: an approved calculator, a ruler and a protractor. Scientific or graphing calculators are both fine.
• Resource sheet: the formulae and the values of physical constants you need come in a separate resource sheet with the exam papers. The acceleration due to gravity is given as g = 9.8 m s⁻².
• Show your reasoning: use numerical working, words and diagrams. Mathematical solutions must show mathematically how two phenomena, concepts or principles are connected.
• Units and figures: give an appropriate unit, keep the number of significant figures consistent with the data in the question, and know the prefixes micro, milli, centi, kilo and mega.
• Contexts that are not in the standard: NZQA says there may be resource-based questions that use motors and generators (you do not need to know the functions of their parts), and ones that use F = mg and balanced forces. The 2027 specification adds that Millikan's oil drop experiment may be used as a context, needing a basic knowledge and interpretation of results.

How NCEA 91173 is marked

The paper has three questions marked N0 to E8, added to a total out of 24: in 2025 they were about electric fields, simple circuits and magnetic fields. NZQA's report advises writing the formula, the substituted values and then the answer, so that a small arithmetic slip still earns partial credit.

NCEA 91173 cut scores

Apart from 2021, when Achieved started at 7 and Merit at 13, the boundaries have sat at 8, 14 and 19. The scores are where each grade begins, out of 24.

Cut scores 2025

2025 schedule: Achieved from 8, Merit from 14, Excellence from 19. The same as 2024.

Cut scores 2024

2024 schedule: Achieved from 8, Merit from 14, Excellence from 19. The same as 2023.

Cut scores 2023

2023 schedule: Achieved from 8, Merit from 14, Excellence from 19. The same as 2022.

Cut scores 2022

2022 schedule: Achieved from 8, Merit from 14, Excellence from 19. Compared with 2021, Achieved went up by 1 and Merit went up by 1.

Cut scores 2021

2021 schedule: Achieved from 7, Merit from 13, Excellence from 19.

Worked examples at each grade

Achieved: a uniform electric field

Two parallel plates 5.0 cm apart have a potential difference of 200 V. Find the field strength, and the force on an electron between them (charge 1.6 × 10⁻¹⁹ C).

The field points from the positive plate to the negative plate, so the force on the electron is the opposite way, towards the positive plate. Convert the 5.0 cm to metres before you divide.

Merit: a circuit with a series resistor

A 12 V battery drives current through a 2.0 Ω resistor, followed by a parallel pair made of a 6.0 Ω and a 12 Ω resistor. Find the current from the battery and the current in the 12 Ω resistor.

Two linked calculations is typical of Merit: work out the total resistance, then use the voltage across the parallel part. Write the formula, the substituted values and the answer, so a small slip still earns partial credit.

Excellence: explaining what changes

Another 12 Ω resistor is added in parallel with the first two. What happens to the current in the 6.0 Ω resistor? Explain without assuming that nothing else changes.

Adding a parallel branch lowers the total resistance, so the current from the source rises from 2.0 A to 2.4 A. That larger current gives a bigger voltage across the 2.0 Ω resistor, so the voltage across the parallel part falls from 8.0 V to 7.2 V, and the current in the 6.0 Ω resistor falls from 1.33 A to 1.2 A. NZQA's 2025 report says candidates lost marks by assuming that when one component changes, everything else stays the same.

Now work out charge, current and energy in our Electricity course, then press Mark to check your answer in the course:

Exam answers

The answers and a worked mark scheme come with today's paper once it is marked. We do not publish official or past paper answers. Every question on the daily paper is our own.

Use the daily paper as a practice exam

The Level 2 Physics track above is a short timed mock of 8 questions, not a full exam and not written by NZQA (NCEA Level 2 Physics). It covers DC circuits, including internal resistance, which supports the circuit part of 91173. It does not cover electric fields, magnetic fields or induced voltage, and it also includes waves, particle physics and materials, which are not part of 91173, so treat those as extra. Use our Electricity course for the field and electromagnetism ideas.

Is NCEA 91173 changing?

NZQA's 2027 specification adds one new note for this standard, about Millikan's oil drop experiment as a possible context. Otherwise the standard stands, and the NZ Certificate of Education replaces Level 2 for Year 12 in 2029.

Common mistakes in NCEA 91173

• Giving magnets electric charges. NZQA's 2025 report lists thinking that magnets have positive and negative poles as a common Not Achieved error.
• Drawing field lines the wrong way. Electric field lines run from positive to negative.
• Confusing V with v. Voltage and velocity are different quantities, so write what each symbol stands for.
• Powers of ten from the calculator. Use the "exp" key for numbers in scientific notation, and write 2.6 × 10⁻⁴, not 2.6E−04.
• Calculations with no labels. State the formula, show the substituted values, then calculate, and say what you are finding at each step.
• Missing non-SI units. Change mm and minutes into m and s before calculating.

Read next

New Zealand · NCEA Level 2NCEA Level 2 Physics formula sheet: every formulaThe NCEA Level 2 Physics formula sheet: every formula for 91170, 91171 and 91173, the constants, what is missing and worked examples.