75-Archetype SyllabusPhysics • ARCH-P-13 • Spec P2

Full 6-Card Lesson 15-Question Timed Drill

UAT-UK SPEC CODE: P2 (Magnetism)ASSUMED MATHS 1 PREREQUISITE: M3.4FREQUENCY: MEDIUM

Electromagnetic Induction (Faraday/Lenz Coil Graphs), AC Generators & Transformer Scaling (V_p/V_s = N_p/N_s)

Deconstructed from 8 past UAT-UK questions (3.43% of all historical Physics papers). Students using standard A-Level classroom methods spend an average of 140s on this archetype—blowing past the 90s ESAT budget. Using the 2-line Sub-90 heuristic below compresses solve time to 35s (saving 105s per question).

Historical Frequency

8 Past Qs

3.43% of Physics

Classroom Trap Time

140s

+50s over 90s budget

Sub-90 Target Time

35s

Banks +105s on the clock

Dominant UI Format

5-Option A–E

Maths 1 Skill: M3.4

Card 1 & Card 2 Preview: The Classroom Time Trap vs. Sub-90 2-Line Rule

Excerpted from our interactive 6-Step Topic Lesson for ARCH-P-13.

Launch All 6 Active-Recall Cards

CARD 1 OF 6 • THE CLASSROOM TIME TRAP (140s)

Why Students Bleed Time:

For an ideal transformer,

I_p V_p = I_s V_s \implies \frac{I_s}{I_p} = \frac{N_p}{N_s}

. Thus secondary current is

I_s = 4 \times \frac{200}{4000} = 0.2\text{ A}

. Power dissipated in the cables is

P = I_s^2 R_{\text{cable}} = (0.2)^2 \times 1500 = 60\text{ W}

(~120s).

In 8 past UAT-UK questions (3.43% of Physics), candidates lose 105s by stepping up voltage by n_s/n_p steps down ideal secondary current by n_p/n_s. Instead, apply P2 with Maths 1 skill M3.4.

CARD 2 OF 6 • THE 2-LINE SUB-90 HEURISTIC (<35s)

Line 1 (Step-Up Steps Down Current):

I_s = I_p \left(\frac{N_p}{N_s}\right) = 4 \times \frac{1}{20} = 0.2\text{ A}

**Line 2 (Cable Heating

I_s^2 R_c

):**

P = (0.2)^2 \times 1500 = 60\text{ W}

(25s).

Sanity & Limit Check: Verify units/signs against multi_statement_linchpin_foil (Statement claiming a step-up transformer increases both voltage and current (violating I_p*V_p = I_s*V_s)) and sign_or_direction_flip (Failing to reverse the polarity of the induced EMF when the bar magnet reverses direction of motion (Lenz's Law)).

Examiner Distractor Blueprint for ARCH-P-13

FOIL #1multi_statement_linchpin_foil

Statement claiming a step-up transformer increases both voltage and current (violating I_p*V_p = I_s*V_s)

Stepping up voltage by N_s/N_p steps down ideal secondary current by N_p/N_s.

Open Multi-Statement Linchpin Foil Clinic

FOIL #2sign_or_direction_flip

Failing to reverse the polarity of the induced EMF when the bar magnet reverses direction of motion (Lenz's Law)

Induced EMF E = -dΦ/dt reverses sign whenever velocity v changes sign, and has larger peak amplitude when return speed is faster.

Open Sign / Direction Flip Clinic

FOIL #3fence_post_or_domain_trap

Assuming induced EMF is maximum when coil plane is perpendicular to magnetic field lines

Maximum flux linkage gives zero rate of change (E = 0); maximum induced EMF occurs when the coil is parallel to B-field lines.

Open Fence-Post / Domain Trap Clinic

FOIL #4subsystem_isolation_trap

Using ideal current ratio I_s = I_p*(N_p/N_s) when the transformer is explicitly stated to be non-ideal (efficiency < 100%)

For a non-ideal transformer, V_s/V_p = N_s/N_p still holds for voltage, but P_out = eff * P_in must be used to find I_s = P_out / V_s.

Open Subsystem Isolation Trap Clinic

Try 1 Live Sample Question Under the 90-Second Stopwatch

Press W to open the 2-line dry-wipe scratchpad, select A–E, and lock in to reveal the Dual-View solution.

Full 6-Card Lesson Launch All 15 Questions (ARCH-P-13)

ARCH-P-13: Electromagnetic Induction (Faraday/Lenz Coil Graphs), AC Generators & Transformer Scaling (V_p/V_s = N_p/N_s) (Sample)Physics

00:00.0

SUB-90 ZONE (<35S)

0.0s35s Sub-9090s ESAT Budget150s Classroom

Question 1 of 1ARCH-P-13 (6-Card Lesson)Format: Standard 5-Option

Right-click any option to cross out • Keys A–E + Enter

Question 1 of 1 • 90s Target

Ready to Start Question 1?

The question stem, diagram, and answer options are hidden behind this pre-start gate. When you click below, the question will reveal and your 90-second split stopwatch will immediately begin ticking.

Physics•ARCH-P-13•Standard 5-Option

or press Enter to start