WORKSHEET – CHAPTER 12: MAGNETIC EFFECTS OF ELECTRIC CURRENT

SECTION A – MULTIPLE CHOICE QUESTIONS (20 MCQs)

  1. Magnetic field is a quantity that has:
     a) Only magnitude
     b) Only direction
     c) Both magnitude and direction
     d) Neither

  2. Magnetic field lines emerge from:
     a) South pole
     b) North pole
     c) Both poles
     d) Centre of magnet

  3. Magnetic field lines never intersect because:
     a) They attract each other
     b) They repel each other
     c) Direction becomes undefined
     d) They are imaginary

  4. The strength of magnetic field around a straight current-carrying conductor:
     a) Increases with distance
     b) Decreases with distance
     c) Remains same
     d) Is zero

  5. The shape of magnetic field around a straight conductor is:
     a) Straight lines
     b) Circular loops
     c) Parabolic curves
     d) No shape

  6. Right-hand thumb rule gives the direction of:
     a) Magnetic field
     b) Current
     c) Force
     d) Torque

  7. Magnetic field inside a solenoid is:
     a) Weak
     b) Zero
     c) Strong and uniform
     d) Only at ends

  8. Electromagnet becomes stronger by:
     a) Increasing current
     b) Increasing turns
     c) Inserting soft iron core
     d) All of these

  9. A solenoid behaves like a:
     a) Battery
     b) Magnet
     c) Capacitor
     d) Conductor

  10. Force on a current-carrying conductor in a magnetic field depends on:
     a) Current
     b) Length of conductor
     c) Strength of magnetic field
     d) All of these

  11. The direction of force on conductor is given by:
     a) Right-hand thumb rule
     b) Fleming’s Left-Hand Rule
     c) Fleming’s Right-Hand Rule
     d) Snell’s Law

  12. Domestic electric supply in India is:
     a) 110 V
     b) 220 V
     c) 440 V
     d) 12 V

  13. Fuse wire has a:
     a) Low melting point
     b) High melting point
     c) High resistance
     d) Both a and c

  14. Overloading happens when:
     a) Many appliances run together
     b) Fuse melts
     c) Earthing wire breaks
     d) Neutral wire breaks

  15. Short circuit occurs when:
     a) Live and earth touch
     b) Neutral and earth touch
     c) Two live wires touch
     d) Live and neutral touch

  16. MCB works on:
     a) Heating effect
     b) Magnetic effect
     c) Chemical effect
     d) Both a and b

  17. Earthing prevents:
     a) Fire
     b) Electric shock
     c) Overloading
     d) Corrosion

  18. A current-carrying conductor placed parallel to magnetic field will experience:
     a) Maximum force
     b) Minimum force
     c) Zero force
     d) Changing force

  19. The north pole of electromagnet depends on:
     a) Direction of current
     b) Number of turns
     c) Material of core
     d) Voltage

  20. In household wiring, appliances are connected in:
     a) Series
     b) Parallel
     c) Both
     d) Neither

SECTION B – ASSERTION & REASON (10 Questions)

  1. A: Magnetic field lines never intersect.
     R: It would give two directions of field at same point.

  2. A: Magnetic field strength decreases with distance.
     R: Magnetic field becomes weaker away from conductor.

  3. A: Solenoid acts like a bar magnet.
     R: It produces uniform magnetic field.

  4. A: Soft iron is used as core in electromagnets.
     R: Soft iron loses magnetism quickly.

  5. A: Fleming’s Left-Hand Rule gives direction of force.
     R: Force depends on direction of current and magnetic field.

  6. A: Fuse protects appliances from damage.
     R: Fuse melts when current exceeds safe limit.

  7. A: MCB is better than fuse.
     R: MCB can be reset and does not melt.

  8. A: Appliances are connected in parallel in homes.
     R: Parallel gives equal voltage to all appliances.

  9. A: Short circuit causes sparks.
     R: It produces large current suddenly.

  10. A: Earthing is essential in homes.
     R: It diverts leakage current safely to ground.

SECTION C – ONE-WORD / VERY SHORT ANSWERS (10)

  1. Define magnetic field.
  2. What is solenoid?
  3. State Right-Hand Thumb Rule.
  4. Write one property of magnetic field lines.
  5. What is electromagnet?
  6. State Fleming’s Left-Hand Rule.
  7. What is a fuse?
  8. What causes overloading?
  9. Why is MCB preferred over fuse?
  10. What is earthing?

SECTION D – SHORT ANSWER QUESTIONS (8)

  1. Draw magnetic field lines around a straight current-carrying conductor.
  2. Describe the magnetic field produced by a solenoid.
  3. How can you increase the strength of an electromagnet?
  4. Explain force on current-carrying conductor with diagram.
  5. Why is soft iron preferred for electromagnets instead of steel?
  6. State differences between bar magnet and electromagnet.
  7. Explain short circuit and overloading with examples.
  8. Why are electrical appliances connected in parallel in household circuits?

SECTION E – LONG ANSWER QUESTIONS (5)

Q1. (Solenoid + Electromagnet – 5 Marks)

(a) Draw magnetic field lines of:
     (i) Straight conductor
     (ii) Solenoid
 (b) Explain why solenoid acts like a bar magnet.
 (c) State three ways to increase strength of electromagnet.
 (d) Write two uses of electromagnets.

Q2. (Force on Conductor – 5 Marks)

(a) State Fleming’s Left-Hand Rule.
 (b) Explain force on a current-carrying conductor with diagram.
 (c) Why is force maximum when conductor is perpendicular to field?
 (d) Give two applications of this force in daily life.

Q3. (Domestic Circuit – Important) – 5 Marks

(a) Draw household wiring diagram showing live, neutral, earth and fuse.
 (b) Explain need of earthing.
 (c) What is overloading? Give two examples.
 (d) What is short circuiting?
 (e) Why is parallel connection used in homes?

Q4. (Magnetic Field Lines – 5 Marks)

(a) Draw magnetic field lines of a bar magnet.
 (b) Write any four properties of magnetic field lines.
 (c) Why do they never intersect?
 (d) Define magnetic field and magnetic field strength.

Q5. (Case-Based – Faulty Domestic Wiring) – 5 Marks

A house uses too many appliances in a single socket extension. Suddenly sparks are seen and MCB trips.

(a) Identify the fault.
 (b) Explain how MCB prevented damage.
 (c) What would have happened if fuse/MCB was absent?
 (d) Why are extension cords risky for heavy appliances?
 (e) Suggest two safety precautions.

 

Scroll to Top