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Current Electricity · Revision Cards · 26 cards

Current Electricity — Revision Cards Hub

Twenty-six worked revision cards for Chapter 3 — resistance-network reduction (ladders, bridges, infinite chains) plus batteries, voltmeters & ammeters, cell groupings and NCERT Examples 3.23 → 3.49. Click any card to open its full walkthrough.

📘 NCERT-Style Worked Examples (8)
Example 3.23

Wire bent into a circle

Resistance across a diameter
Example 3.24

Equivalent resistance A–B

Network reduction
Example 3.26

Resistance A–B and A–D

Two reference points
Example 3.27

Effective resistance A–B

Ladder network
Example 3.28

Equivalent resistance of a ladder

Ladder reduction
Example 3.29

Equivalent resistance A–B

Hidden parallel
Example 3.32(i)

R between P and Q

Symmetric bridge
Example 3.33

Infinite ladder — R between A and B

Self-similar trick
🔢 Numbered Q-cards (4)
Q29 · Q30

Resistance between two points

Triangle / bridge
Q60

Equivalent resistance A–B

Five resistors with jumpers
Q101 · Q102

Equivalent resistance A–B

Bridge problem
Ammeter Reading

Redrawn 12 V Network

Find I through the ammeter
🛠 Reduction Techniques (3)
Technique

Symmetry reduction

R between A and B
Technique

Reducing the jumpered chain

R between A and B
Network

Equivalent resistance A–E

Five-node network
🔋 Cells · Voltmeters · Ammeters · Ex 3.34 → 3.49 (11)
Example 3.34

EMF & internal resistance

Voltmeter reading of a cell
Example 3.35

Battery, ammeter & resistor in series

Circuit current with real cell
Example 3.36

Real voltmeter — % error

Finite meter resistance
Example 3.37

Crossed-square network

Reduction by node-merging
Example 3.38

PD across two batteries (aiding)

Cells in series
Example 3.39

Equivalent battery — series + parallel

Combined EMF & \(r_{\text{eq}}\)
Example 3.40

Cells in parallel

Weighted-average EMF form
Example 3.41

Minimum cells — mixed grouping

Choose \(n, m\) to meet load
Example 3.42

Best grouping of 36 cells

Max current for fixed total
Example 3.43

Max current — 12 cells

Optimize \(R = nr/m\)
Example 3.49

Maximum power rating

Safe-current from wattage