E ExamMaster

CBSE Class 10 · Science

Electricity

Official NCERT chapter from Science (book code jesc1). ExamMaster notes are original teaching at CBSE Class 10 depth.

This lesson follows the official chapter “Electricity” in Science. The words below are ExamMaster’s teaching, not a paste from the book. Use the NCERT chapter for the classroom sequence; use these notes to hold the idea without copying exercises or figures.

  • CBSE Class 10
  • Medium level
  • 8 concepts

1ELECTRIC CURRENT AND CIRCUIT

Electric current is a flow of charge in a closed loop; a circuit is that loop from the cell through the parts and back. A gap stops the current. Current is the flow-word; the circuit is the path. A lit bulb is a look that the loop closed.

A battery photo with no loop is not a circuit.

Figure. Current needs a closed loop: cell, key, lamp, return. An open key is a gap, not almost on.

How it works

  1. Draw a closed path through the cell and the bulbThe circuit.
  2. Name the flow as currentThe heading.
  3. Open a gap and the look failsClosed loop.

2ELECTRIC POTENTIAL AND POTENTIAL DIFFERENCE

Potential difference is the school push between two points that can drive current (volt as the unit). A cell has a named PD; a wire-point compared to another is the between. PD is not current — it can sit there with a gap and no flow.

Calling 1.5 V “the current” is the heading-steal.

Figure. Potential is electrical height. The difference V is what a voltmeter reads between the two terminals.

How it works

  1. Name two pointsThe between.
  2. Name the push (volt)The PD.
  3. Keep current as the flow that may resultTwo words.

3CIRCUIT DIAGRAM

A circuit diagram uses taught symbols: cell, bulb, switch, resistor, as the lesson drew them. Diagram is a map, not an art sketch of a torch. A switch open is a gap in the map.

A 3-d torch drawing is not this diagram.

Figure. A school circuit diagram is a map of symbols: cell, key, ammeter, resistor, return. The zigzag is the resistor.

How it works

  1. Place the symbols in a loopThe map.
  2. Mark the switch open or closedThe gap or not.
  3. Read current only if the loop closesThe diagram’s job.

4OHM’S LAW

Ohm’s law: V = I R when the school resistor stays ohmic (as taught). 6 V across 3 Ω is 2 A. A bulb that changes R as it heats may leave the straight-line story — the lesson’s caution if it gave one.

Using V = I R with R unnamed is a stolen letter.

Figure. Ohm’s law is the straight V–I line through the origin. At 2 A the drop is 4 V, so R = 2 ohm.

How it works

  1. Name V and R (or I and R)The given.
  2. Write V = I RThe law.
  3. Keep the unit V, A, ΩOhmic as taught.

6 V, 3 Ω

A 3 Ω ohmic resistor has 6 V across it. Find the current.

  • I = V/R6/3
  • I2 A
  • ReadOhmic; units A

Pro tip. V = I R; the gap-less loop is assumed.

5FACTORS ON WHICH THE RESISTANCE OF A CONDUCTOR DEPENDS

Resistance of a conductor depends on length, thickness, material, and temperature as taught: longer raises R, thicker lowers R, a taught material-constant sits in the write. Depend is a compare, not “resistance is bad”.

A short fat copper and a long thin nichrome (as a school pair) are not the same R.

Figure. Resistance grows with length and falls with thickness. The long thin bar is the larger R.

How it works

  1. Compare length, thickness, materialThe factors.
  2. Say which way R movesThe depend.
  3. Keep temperature if the lesson named itThe list.

6RESISTANCE OF A SYSTEM OF RESISTORS

A system of resistors: series adds (R = R1+R2); parallel shares (1/R = 1/R1+1/R2) as taught. 2 Ω and 4 Ω in series is 6 Ω; in parallel is 4/3 Ω. System means you name series or parallel first.

Adding 2 and 4 in parallel as 6 is the series-steal.

Figure. Series stacks R on one path. Parallel gives two paths between the same ends, so the pair is easier than one R.

How it works

  1. Name series or parallelThe system.
  2. Add, or take the reciprocal-sumThe combine.
  3. Then I or V if askedThe network.

7HEATING EFFECT OF ELECTRIC CURRENT

Heating effect: a current through a resistance can warm it — I² R t as the school write if taught, or P = I² R. A heater-coil is this job; a good connecting wire is meant not to be. Heat is the leftover-job of current, not a second electricity.

A warm phone-charger brick may be this look — still I and R, not “magic heat”.

Figure. A current in a coil pays as heat. H grows with I squared, with R, and with time.

How it works

  1. Name I and R (and t if asked)The given.
  2. Write the taught heat-formThe effect.
  3. Keep it on the coil that is meant to warmHonest job.

8ELECTRIC POWER

Electric power is how fast electrical work is done: P = V I (and the taught twins P = I² R, P = V²/R). 6 V and 2 A is 12 W. Power is the rate, not the bill’s rupee by itself.

Calling a 12 W bulb “12 volts” is a unit-swap.

Figure. Power is the energy rate. The heater bar is five times the lamp because it draws energy five times as fast.

How it works

  1. Name V and I (or the twin pair)The given.
  2. Multiply as P = V IThe power.
  3. Keep the wattThe rate.
6 V across 3 Ω (ohmic) gives I
  1. 2 A
  2. 18 A
  3. 3 A

I = V/R = 2.

Notes

  • Mapped to the official NCERT chapter “Electricity”. Original teaching only — no textbook sentences.
  • Science here is Physics, Chemistry and Biology ideas at this class, never a language or social-science chapter.

Formulas

  • V = I R (ohmic)
  • series: R=R1+R2
  • parallel: 1/R=1/R1+1/R2
  • P = V I

Recap

Hold these pegs from the official chapter “Electricity”. The wording is ExamMaster’s teaching, not a textbook recap.

ELECTRIC CURRENT AND CIRCUIT
Electric current is a flow of charge in a closed loop; a circuit is that loop from the cell through the parts and back.
ELECTRIC POTENTIAL AND POTENTIAL DIFFERENCE
Potential difference is the school push between two points that can drive current (volt as the unit).
CIRCUIT DIAGRAM
A circuit diagram uses taught symbols: cell, bulb, switch, resistor, as the lesson drew them.
OHM’S LAW
Ohm’s law: V = I R when the school resistor stays ohmic (as taught).
FACTORS ON WHICH THE RESISTANCE OF A CONDUCTOR DEPENDS
Resistance of a conductor depends on length, thickness, material, and temperature as taught: longer raises R, thicker lowers R, a taught material-constant sits in the write.
RESISTANCE OF A SYSTEM OF RESISTORS
A system of resistors: series adds (R = R1+R2); parallel shares (1/R = 1/R1+1/R2) as taught.

Practise Electricity

Reading is free and needs no account. Practice, mocks and progress live in the app.

  • A 4-question practice set that ends the chapter
  • 1 quick check with worked explanations
  • Timed mocks scored with the real marking scheme
  • Readiness tracked per topic, kept on your device
Continue with Google — freeNo card, no trial. Works offline once installed.