Magnetic Effects of Electric Current Topic Hub

Magnetic Effects of Electric Current — Class 10 Notes

CBSE 2027 — dates, rules and official papers →
Physics · Ch 12Class 10 · CBSE 2026–27Medium weightage

Magnetic Effects of Electric Current

What the board actually asks: the two direction rules (right-hand thumb rule for the field around a wire, Fleming's left-hand rule for the force on a wire), the properties of magnetic field lines, the field pattern of a solenoid compared with a bar magnet, and why a current-carrying conductor in a magnetic field feels a force — plus the domestic-circuit safety questions (live / neutral / earth wire, fuse, earthing, overloading and short-circuit) and the AC-vs-DC contrast with the 50 Hz supply frequency. These are mostly 1-3 mark direction-and-reasoning questions, not numericals.

NCERT VERBATIM sourced, word-for-wordAUTHORED LazyTopper teaching scaffolding
The Big Idea AUTHORED

A current makes a magnet; a magnet pushes a current.

Every electric current wraps a magnetic field around itself, and a current-carrying wire placed in someone else's magnetic field feels a sideways push. Two hand rules capture the geometry: the right-hand thumb rule tells you which way the field curls around a wire, and Fleming's left-hand rule tells you which way the force pushes the wire. At home the same physics ends in a wall socket: 220 V alternating current at 50 Hz, carried by live, neutral and earth wires and protected by a fuse.

Formulae
Field vs current (straight wire)
Tip: B ∝ I.
Field vs distance (straight wire)
Tip: B ∝ 1/r.
Coil of turns
Tip: n × the single-turn field.
Mains supply in India
AC, , — live (red) · neutral (black) · earth (green)
Tip: 220 V (NCERT 12.4); 50 Hz appears in the NCERT chapter summary and the CBSE syllabus line "frequency of AC".
Oersted's Experiment
A compass needle placed near a wire carrying a current is deflected, so a current produces a magnetic field. When the direction of the current is reversed, the deflection reverses.

Magnetic Field Lines: Properties

Properties of field lines
Outside a magnet the field lines emerge from the north pole and enter the south pole; inside the magnet they run from south to north, so they are closed curves. No two field lines cross each other. Where the lines are closer together the field is stronger.

Right-Hand Thumb Rule

Statement
Imagine holding a straight current-carrying wire in your right hand with the thumb pointing along the direction of the current. The fingers then wrap around the wire in the direction of the magnetic field lines.

Magnetic Field of a Solenoid

Field of a solenoid
A solenoid is a coil of many circular turns of insulated wire wrapped like a cylinder. The field pattern around it is like that of a bar magnet: one end behaves as a north pole and the other as a south pole. Inside a long straight solenoid the field is uniform (the same at all points). A soft-iron core inside a solenoid makes an electromagnet.
Force on a Current-carrying Conductor
A conductor carrying a current placed in a magnetic field experiences a force. The force is largest when the current is perpendicular to the field, and its direction reverses when the direction of the current is reversed.

Fleming's Left-Hand Rule

Statement
Stretch the thumb, forefinger and middle finger of your left hand so that they are mutually perpendicular. If the forefinger points along the magnetic field and the middle finger along the current, the thumb points in the direction of the force (motion) on the conductor.

Domestic Electric Circuits

Wires, fuse and earthing
Our supply has a live wire (red insulation), a neutral wire (black) and an earth wire (green); the potential difference between live and neutral is 220 V. The earth wire is connected to the metal body of appliances to prevent shocks. A fuse in the circuit protects against overloading and short-circuiting. In a house, a 5 A circuit is used for bulbs and fans and a 15 A circuit for geysers and air coolers.

Direct Current and Alternating Current

Direct and alternating current
Direct current (DC) flows in one direction only, as from a battery of dry cells. Alternating current (AC) reverses its direction at regular intervals; the frequency of the AC supply in India is 50 Hz. AC is better for long-distance transmission of power because it can be sent over long distances without much loss of electric energy. Household supply is AC.

Shortcuts & memory tricks →

Definitions the board rewards NCERT VERBATIM

State these in NCERT’s exact words

Magnetic field
NCERT verbatim — memorise this exact wording· Ch 12,
“The region surrounding a magnet, in which the force of the magnet can be detected, is said to have a magnetic field.”
What it means: the space around a magnet where its pull or push can be felt. It is a vector — it has both a direction and a magnitude.
Magnetic field lines
NCERT verbatim — memorise this exact wording· Ch 12,
“The lines along which the iron filings align themselves represent magnetic field lines.”
What it means: the imaginary curves that map a magnetic field. A tiny compass placed on a line points along it, so a field line is the path a free north pole would follow.
Direction of the magnetic field
NCERT verbatim — memorise this exact wording· Ch 12,
“Magnetic field is a quantity that has both direction and magnitude. The direction of the magnetic field is taken to be the direction in which a north pole of the compass needle moves inside it.”
What it means: point a compass anywhere in the field — the way its north pole turns is the field direction at that spot.
Field lines are closed curves
NCERT verbatim — memorise this exact wording· Ch 12,
“Therefore it is taken by convention that the field lines emerge from north pole and merge at the south pole (note the arrows marked on the field lines in Fig. 12.4). Inside the magnet, the direction of field lines is from its south pole to its north pole. Thus the magnetic field lines are closed curves.”
What it means: outside the magnet field lines run N → S; inside they run S → N, so each line closes on itself. They never simply start or stop in mid-air.
Field strength and closeness of lines
NCERT verbatim — memorise this exact wording· Ch 12,
“The relative strength of the magnetic field is shown by the degree of closeness of the field lines. The field is stronger, that is, the force acting on the pole of another magnet placed is greater where the field lines are crowded (see Fig. 12.4).”
What it means: crowded lines mean a strong field (near the poles); widely spaced lines mean a weak field.
Right-hand thumb rule
NCERT verbatim — memorise this exact wording· Ch 12,
“Imagine that you are holding a current-carrying straight conductor in your right hand such that the thumb points towards the direction of current. Then your fingers will wrap around the conductor in the direction of the field lines of the magnetic field, as shown in Fig. 12.7. This is known as the right-hand thumb rule.”
What it means: grip the wire with your right hand, thumb along the current; your curled fingers show which way the circular field lines go around the wire.
Solenoid
NCERT verbatim — memorise this exact wording· Ch 12,
“A coil of many circular turns of insulated copper wire wrapped closely in the shape of a cylinder is called a solenoid.”
What it means: a long, tightly wound cylindrical coil. Carrying current, it behaves like a bar magnet.
Uniform field inside a solenoid
NCERT verbatim — memorise this exact wording· Ch 12,
“The field lines inside the solenoid are in the form of parallel straight lines. This indicates that the magnetic field is the same at all points inside the solenoid. That is, the field is uniform inside the solenoid.”
What it means: deep inside the coil the field is the same everywhere — same strength and direction (a uniform field).
Electromagnet
NCERT verbatim — memorise this exact wording· Ch 12,
“A strong magnetic field produced inside a solenoid can be used to magnetise a piece of magnetic material, like soft iron, when placed inside the coil (Fig. 12.11). The magnet so formed is called an electromagnet.”
What it means: put a soft-iron core inside a current-carrying solenoid and it becomes a strong magnet — an electromagnet — only while the current flows.
Fleming's left-hand rule
NCERT verbatim — memorise this exact wording· Ch 12,
“According to this rule, stretch the thumb, forefinger and middle finger of your left hand such that they are mutually perpendicular (Fig. 12.13). If the first finger points in the direction of magnetic field and the second finger in the direction of current, then the thumb will point in the direction of motion or the force acting on the conductor.”
What it means: left hand, three fingers at right angles: First finger = Field, seCond finger = Current, thuMb = Motion (force). It gives the direction of the push on the wire.
Live and neutral wires (220 V)
NCERT verbatim — memorise this exact wording· Ch 12,
“One of the wires in this supply, usually with red insulation cover, is called live wire (or positive). Another wire, with black insulation, is called neutral wire (or negative). In our country, the potential difference between the two is 220 V.”
What it means: the two wires that actually power an appliance: red = live, black = neutral, 220 V between them. Every appliance is connected across these two.
Earth wire (earthing)
NCERT verbatim — memorise this exact wording· Ch 12,
“The earth wire, which has insulation of green colour, is usually connected to a metal plate deep in the earth near the house. This is used as a safety measure, especially for those appliances that have a metallic body, for example, electric press, toaster, table fan, refrigerator, etc.”
What it means: the green third wire. It joins the metal body of an appliance to the earth, giving any leaked current a low-resistance path so the body stays at earth potential and the user is not shocked.
Overloading and short-circuiting
NCERT verbatim — memorise this exact wording· Ch 12,
“Overloading can occur when the live wire and the neutral wire come into direct contact. (This occurs when the insulation of wires is damaged or there is a fault in the appliance.) In such a situation, the current in the circuit abruptly increases. This is called short-circuiting.”
What it means: a short circuit is live touching neutral — the current jumps. Overloading also happens when the supply voltage spikes or too many appliances hang off one socket.
Key terms — NCERT verbatim (state word-for-word)
No two field lines cross
No two field-lines are found to cross each other. If they did, it would mean that at the point of intersection, the compass needle would point towards two directions, which is not possible. (Ch 12, )
Field around a straight wire
The field lines about the wire consist of a series of concentric circles whose direction is given by the right-hand rule. (Ch 12, )
When the force is largest
Experiments have shown that the displacement of the rod is largest (or the magnitude of the force is the highest) when the direction of current is at right angles to the direction of the magnetic field. (Ch 12, )
Electric fuse
The use of an electric fuse prevents the electric circuit and the appliance from a possible damage by stopping the flow of unduly high electric current. The Joule heating that takes place in the fuse melts it to break the electric circuit. (Ch 12, )
Appliances in parallel
In order that each appliance has equal potential difference, they are connected parallel to each other. (Ch 12, )
AC supply: 220 V, 50 Hz
In our houses we receive AC electric power of 220 V with a frequency of 50 Hz. (Ch 12, )
Must-know concepts AUTHORED FRAMING

…and where they’re tested

Magnetic field lines and their properties
Field lines picture the field: they run from N to S outside a magnet and close inside it, they are crowded where the field is strong, and no two ever cross. These four properties are the standard short-answer.
NCERT Fig 12.4Field lines around a bar magnet — they emerge from N, merge at S, are crowded near the poles and never cross.
Arrows run north → south outside the magnet; the lines close on themselves inside it.
2–3 mark "list the properties of magnetic field lines" / "why don't two field lines cross?"
Magnetic field due to a straight current-carrying conductor
A straight wire is surrounded by concentric circular field lines. Their direction is found by the right-hand thumb rule; the field grows with the current () and weakens with distance ().
NCERT Fig 12.7Right-hand thumb rule — thumb along the current, curled fingers give the circular magnetic field.
The circle of arrows shows the field wrapping around the straight current-carrying conductor.
2-mark "find the direction of the field" using the right-hand thumb rule
Field due to a circular loop and a coil
Bend the wire into a loop and every part of it pushes the field the same way through the centre, so the field there is strong and nearly straight. A coil of turns gives times the field of a single turn, because each turn adds up.
2-mark reasoning "why is the field stronger at the centre of a coil?"
Solenoid and the electromagnet
A current-carrying solenoid has a field pattern identical to a bar magnet — one end a north pole, the other a south pole — and a uniform field inside. A soft-iron core inside it becomes a strong electromagnet.
NCERT Fig 12.10Field lines through and around a current-carrying solenoid — identical to a bar magnet, uniform inside.
One end of the solenoid acts as a north pole, the other as a south pole; inside, the lines are parallel.
3-mark "compare the field of a solenoid with a bar magnet" / electromagnet
Force on a current-carrying conductor
A wire carrying current in a magnetic field feels a force perpendicular to both. The force is largest when the current is at right angles to the field, and it reverses if either the current or the field is reversed. Its direction is read off Fleming's left-hand rule.
NCERT Fig 12.13Fleming's left-hand rule — forefinger = field, second finger = current, thumb = force/motion.
The three fingers of the left hand are held mutually perpendicular to give the three directions.
2–3 mark "state the rule / find the direction of the force"
Direct current and alternating current
A cell or battery drives a direct current (DC) — it flows in one direction only. The mains supply is an alternating current (AC) that reverses its direction periodically; in India it is 220 V at a frequency of 50 Hz, so the current completes 50 cycles every second (it changes direction every 1/100 s). The board-listed advantage of AC over DC: electric power can be transmitted over long distances without much loss of energy, which is why the grid delivers AC to homes.
1-mark recall (frequency of AC in India) · 2-mark distinguish AC from DC / state one advantage of AC over DC
Domestic electric circuits — live, neutral, earth, fuse
Mains power enters through a main fuse and the meter, then splits into separate circuits — a 15 A circuit for high-power appliances (geysers, air coolers) and a 5 A circuit for bulbs and fans. Each appliance sits in parallel across the live (red) and neutral (black) wires, so every one gets the full 220 V and has its own switch. The green earth wire ties metal bodies to the earth so a leak cannot shock the user. A fuse melts by Joule heating when the current rises too high — through short-circuiting (live touching neutral), a voltage surge, or too many appliances on one socket (overloading).
NCERT Fig 12.15A common domestic circuit — live (red) and neutral (black) come from the mains through the Electricity Board's fuse, the electricity meter and the distribution box (main switch plus a fuse for each circuit); every socket sits across the 220 V live–neutral pair, in parallel; the earth wire (green) runs to the earth pin of each socket.
Follow the red wire left to right: fuse → meter → distribution box → top rail. Each socket hangs between the red and black rails (parallel, so each gets the full 220 V); the green wire crosses the live rail without joining it (the small jump) and ends on the socket's earth pin.
2–3 mark 'function of the earth wire / why are appliances connected in parallel / when does a short circuit occur' (NCERT Exercise Q8, Q9) · 1-mark true/false on wire colours (Exercise Q6)
Worked examples — real solved problems NCERT VERBATIM

Solved exactly as the source does them

Every problem is a real sourced item, quoted verbatim with its page; the step-by-step decoding and mark-logic are LazyTopper-authored coaching.

Example 12.1,
“A current through a horizontal power line flows in east to west direction. What is the direction of magnetic field at a point directly below it and at a point directly above it?”
Note the current direction.The current is along the wire, from east to west.Concept: set up the rule
Apply the right-hand thumb rule.Point the right thumb from east to west (along the current); the curled fingers give the field, which lies in a plane perpendicular to the wire.Concept: right-hand thumb rule
1 mark
Read off the direction.The magnetic field turns clockwise when viewed from the east end and anti-clockwise when viewed from the west end — so at the point below the wire and the point above it, the field points in opposite directions.Concept: below vs above
1 mark
Mark-scheme logic (authored): 1 mark for correctly applying the right-hand thumb rule, 1 mark for the clockwise/anti-clockwise sense (equivalently, that the field is oppositely directed below and above the wire).
Example 12.2,
“An electron enters a magnetic field at right angles to it, as shown in Fig. 12.14. The direction of force acting on the electron will be (a) to the right. (b) to the left. (c) out of the page. (d) into the page.”
Problem-solving strategies AUTHORED
Field AROUND a wire?Right hand — thumb along the current, curled fingers give the circular field. Reverse the current and the field reverses.
Force ON a wire?Fleming's LEFT hand — First finger Field, seCond finger Current, thuMb Motion/force. Don't reach for the right hand here.
Solenoid question?Say it out loud: its field is identical to a bar magnet, uniform inside, one end N and one end S; a soft-iron core makes an electromagnet.
"Properties of field lines"?Four marks-earners: N→S outside / closed curves / crowded = strong / never cross.
Domestic circuit question?Name the wire by colour and job — red live, black neutral, green earth — then give the safety reason: earthing for metal bodies, fuse (melts by Joule heating) against overloading and short-circuit, appliances in parallel so each gets 220 V.
AC or DC?DC flows one way (cells, batteries); AC reverses periodically — 220 V, 50 Hz in India. Advantage of AC: long-distance transmission without much loss of energy.
Common mistakes that cost marks

Where students lose easy marks

✗ Swapping the two rules — use the RIGHT hand for the field around a wire, the LEFT hand for the force on a wire.
✗ In the electron problem, forgetting that conventional current is opposite to the electron's motion — it flips the force direction.
✗ Calling field lines open — they are closed curves (S→N inside the magnet).
✗ Drawing two field lines that cross — impossible, since a compass can't point two ways at once.
✗ Calling the green wire the live wire — NCERT's own true/false item (Exercise Q6) sets this trap. Red is live, black neutral, green earth.
Formulae
Field vs current (straight wire)
Tip: B ∝ I.
Field vs distance (straight wire)
Tip: B ∝ 1/r.
Coil of turns
Tip: n × the single-turn field.
Mains supply in India
AC, , — live (red) · neutral (black) · earth (green)
Tip: 220 V (NCERT 12.4); 50 Hz appears in the NCERT chapter summary and the CBSE syllabus line "frequency of AC".
Oersted's Experiment
A compass needle placed near a wire carrying a current is deflected, so a current produces a magnetic field. When the direction of the current is reversed, the deflection reverses.

Magnetic Field Lines: Properties

Properties of field lines
Outside a magnet the field lines emerge from the north pole and enter the south pole; inside the magnet they run from south to north, so they are closed curves. No two field lines cross each other. Where the lines are closer together the field is stronger.

Right-Hand Thumb Rule

Statement
Imagine holding a straight current-carrying wire in your right hand with the thumb pointing along the direction of the current. The fingers then wrap around the wire in the direction of the magnetic field lines.

Magnetic Field of a Solenoid

Field of a solenoid
A solenoid is a coil of many circular turns of insulated wire wrapped like a cylinder. The field pattern around it is like that of a bar magnet: one end behaves as a north pole and the other as a south pole. Inside a long straight solenoid the field is uniform (the same at all points). A soft-iron core inside a solenoid makes an electromagnet.
Force on a Current-carrying Conductor
A conductor carrying a current placed in a magnetic field experiences a force. The force is largest when the current is perpendicular to the field, and its direction reverses when the direction of the current is reversed.

Fleming's Left-Hand Rule

Statement
Stretch the thumb, forefinger and middle finger of your left hand so that they are mutually perpendicular. If the forefinger points along the magnetic field and the middle finger along the current, the thumb points in the direction of the force (motion) on the conductor.

Domestic Electric Circuits

Wires, fuse and earthing
Our supply has a live wire (red insulation), a neutral wire (black) and an earth wire (green); the potential difference between live and neutral is 220 V. The earth wire is connected to the metal body of appliances to prevent shocks. A fuse in the circuit protects against overloading and short-circuiting. In a house, a 5 A circuit is used for bulbs and fans and a 15 A circuit for geysers and air coolers.

Direct Current and Alternating Current

Direct and alternating current
Direct current (DC) flows in one direction only, as from a battery of dry cells. Alternating current (AC) reverses its direction at regular intervals; the frequency of the AC supply in India is 50 Hz. AC is better for long-distance transmission of power because it can be sent over long distances without much loss of electric energy. Household supply is AC.
Shortcuts & Tricks
Field lines never cross; closer lines mean a stronger field.
MCQ / check only: don't write this as working
Right-hand THUMB rule = direction of the FIELD from a current. Fleming's LEFT-hand rule = direction of the FORCE. Do not swap them.
MCQ / check only: don't write this as working
The force is perpendicular to both the field and the current.
MCQ / check only: don't write this as working
Colours: red live, black neutral, green earth. The fuse goes in the live wire.
MCQ / check only: don't write this as working
Field inside a long straight solenoid is the same at every point.
MCQ / check only: don't write this as working
Memory Tricks
Taar ko mutthi mein pakdo: angootha = bijli ki disha, lipti ungliyan = chumbakiy kshetra.
Right-hand thumb rule. thumb = current direction; curled fingers = field direction.
Angootha = Taakat, Pehli ungli = Field, Beech wali = Bijli.
Fleming's left-hand rule. thumb = force (motion); forefinger = field; middle finger = current.
N se nikle, S mein ghuse (bahar); magnet ke andar S se N.
Field line direction. outside N→S; inside S→N.
Laal = Live, Kaala = Neutral, Hara = Earth.
Wire colours. red live · black neutral · green earth.
Paanch ampere: bulb-pankha. Pandrah ampere: geyser-cooler.
Circuit ratings. 5 A for bulbs and fans; 15 A for geysers, air coolers.
Mindmap
      • Field = region where a magnet's force is felt
      • Lines emerge N, merge S — closed curves
      • Crowded = strong; spaced = weak
      • No two lines cross
      • Straight wire → concentric circles
      • Right-hand thumb rule (direction)
      • B ∝ I ; B ∝ 1/r
      • Solenoid = bar magnet, uniform inside
      • Soft-iron core → electromagnet
      • Current in a field feels a force
      • Largest when current ⊥ field
      • Fleming's left-hand rule (direction)
      • Force reverses if I or field reverses
      • Live (red), neutral (black), earth (green)
      • 220 V AC at 50 Hz
      • Appliances in parallel, each with a switch
      • Fuse melts on overloading / short circuit
      • DC one way; AC reverses — long-distance transmission
      • Right-hand (field) vs left-hand (force)
      • Field lines are closed, not open
      • Current is opposite to electron motion
      • Green = earth, never live

This chapter is about DIRECTIONS, not formulas. Two hand rules do almost all the work — keep them straight, and note how the field's size changes with current and distance. The last two blocks are the household end: wire colours, the fuse, and AC versus DC.

NCERT Fig 12.7Right-hand thumb rule — thumb along the current, curled fingers give the circular magnetic field.
The circle of arrows shows the field wrapping around the straight current-carrying conductor.
Right-hand thumb rule — direction of the field around a straight wire
Grip the wire with your right hand.
Point the thumb along the direction of the current.
The curled fingers give the direction of the circular field lines.
Reverse the current and the field direction reverses.

Fleming's left-hand rule — direction of the force on the wire

  • First fingerpoints along the magnetic Field.
  • seCond fingerpoints along the Current (conventional).
  • thuMbpoints along the Motion / force on the conductor.

Properties of magnetic field lines

  • N→SOutside the magnet lines run north to south; inside, south to north — so they are closed curves.
  • ≠No two field lines ever cross (a compass cannot point two ways).
  • ≡Crowded lines = strong field; widely spaced lines = weak field.

How the field strength changes

  • +Larger current → stronger field ().
  • −Farther from the wire → weaker field ().
  • ×nA coil of turns gives times the field of one turn.

Domestic circuit — wire colours and safety

  • RedLive wire — 220 V with respect to the neutral.
  • BlackNeutral wire — the return path.
  • GreenEarth wire — ties metallic bodies to the earth so leaked current cannot shock the user.
  • FuseMelts by Joule heating on overloading or a short circuit, breaking the circuit.
  • ∥Appliances are connected in parallel — each gets the full potential difference and its own switch.
  • 15 A / 5 ASeparate circuits for high-power appliances (geysers, coolers) and for bulbs and fans.
Direct current vs alternating current
DC (cells, batteries) flows in one direction only.
AC reverses its direction periodically — India's supply is 220 V at 50 Hz.
Advantage of AC over DC: it can be transmitted over long distances without much loss of energy.

3 competency questions from the CBSE board pattern, with the full step-marked solution for each — the marks are shown per step, as the official scheme awards them.

1 markSection ACBSE 2024

The current carrying device which produces a magnetic field similar to that of a bar magnet is :

  1. (A) A straight conductor
  2. (B) A circular loop
  3. (C) A solenoid
  4. (D) A circular coil
Step-marked solution
  1. [1 mark] The magnetic field lines of a current-carrying solenoid emerge from one end and enter the other, exactly like a bar magnet; one end acts as a north pole and the other as a south pole. Hence (c) a solenoid.
3 marksSection CCBSE 2024

A student fixes a sheet of white paper on a drawing board. He places a bar magnet in the centre of it. He sprinkles some iron filings uniformly around the bar magnet. Then he taps the drawing board gently and observes that the iron filings arrange themselves in a particular pattern. (a) Why do iron filings arrange in a particular pattern ? (b) What does the crowding of iron filings at the ends of the magnet indicate ? (c) What do the lines, along which the iron filings align, represent ? (d) If the student places a cardboard horizontally in a current carrying solenoid and repeats the above activity, in what pattern would the iron filings arrange ? State the conclusion drawn about the magnetic field based on the observed pattern of the lines.

Step-marked solution
  1. [1 mark] (a) Because a magnetic field exists around the bar magnet
  2. [1 mark] (b) Strength of the magnetic field is maximum near the poles of the magnet
  3. [1 mark] (c) The lines represent the magnetic field lines. (d) Equidistant parallel lines; the magnetic field inside the solenoid is uniform.
1 markSection ACBSE 2025

Which one of the following statements is not true about a bar magnet ?

  1. (A) It sets itself in north-south direction when suspended freely.
  2. (B) It has attractive power for iron filings.
  3. (C) It produces magnetic field lines.
  4. (D) The direction of magnetic field lines inside a bar magnet is from its north pole to its south pole.
Step-marked solution
  1. [1 mark] Correct option: (d) The direction of magnetic field lines inside a bar magnet is from its north pole to its south pole.
Practise Magnetic Effects of Electric Current competency questions

Read NCERT Chapter 12 on LazyTopper (jesc112)

Official NCERT chapter PDF (jesc112) — ncert.nic.in

Sources: NCERT 2026-27 (tap to view)
Source ledger PROVENANCE

Source edition: NCERT Reprint 2026-27, Class 10 Science, Ch 12. One row per sourced item — every verbatim, example and NCERT figure traces to its page.

ItemTypeSource
Magnetic fieldverbatimNCERT 2026-27 Ch12
Magnetic field linesverbatimNCERT 2026-27 Ch12
Direction of the magnetic fieldverbatimNCERT 2026-27 Ch12
Field lines are closed curvesverbatimNCERT 2026-27 Ch12
Field strength and closeness of linesverbatimNCERT 2026-27 Ch12
Right-hand thumb ruleverbatimNCERT 2026-27 Ch12
SolenoidverbatimNCERT 2026-27 Ch12
Uniform field inside a solenoidverbatimNCERT 2026-27 Ch12
ElectromagnetverbatimNCERT 2026-27 Ch12
Fleming's left-hand ruleverbatimNCERT 2026-27 Ch12
No two field lines crossverbatimNCERT 2026-27 Ch12
Field around a straight wireverbatimNCERT 2026-27 Ch12
When the force is largestverbatimNCERT 2026-27 Ch12
Live and neutral wires (220 V)verbatimNCERT 2026-27 Ch12
Earth wire (earthing)verbatimNCERT 2026-27 Ch12
Overloading and short-circuitingverbatimNCERT 2026-27 Ch12
Electric fuseverbatimNCERT 2026-27 Ch12
Appliances in parallelverbatimNCERT 2026-27 Ch12
AC supply: 220 V, 50 HzverbatimNCERT 2026-27 Ch12 (Summary)
Right-hand thumb rule — field near a power lineexampleNCERT 2026-27 Ch12 Ex 12.1
Fleming's left-hand rule — force on a moving electronexampleNCERT 2026-27 Ch12 Ex 12.2
NCERT Fig 12.4figureNCERT 2026-27 Ch12 Fig 12.4
NCERT Fig 12.7figureNCERT 2026-27 Ch12 Fig 12.7
NCERT Fig 12.10figureNCERT 2026-27 Ch12 Fig 12.10
NCERT Fig 12.13figureNCERT 2026-27 Ch12 Fig 12.13
NCERT Fig 12.15figureNCERT 2026-27 Ch12 Fig 12.15

Magnetic Effects of Electric Current · spec-rendered note · NCERT Reprint 2026-27, Class 10 Science, Ch 12

Practise writing answers the way examiners mark them → Guide