Magnetic Effects of Electric Current : āĻŦ⧈āĻĻā§āϝ⧁āϤāĻŋāĻ• āϧāĻžā§°āĻžā§° āϚ⧁āĻŽā§āĻŦāϕ⧀āϝāĻŧ āĻĒā§ā§°āĻ­āĻžā§ą : PYQ 2 : BOARD PYQ QUESTIONS : āĻŦā§‹ā§°ā§āĻĄā§° āϗ⧁⧰⧁āĻ¤ā§āĻŦāĻĒā§‚ā§°ā§āĻŖ āĻĒā§ā§°āĻļā§āύ








1 Mark Questions : ā§§ āύāĻŽā§āĻŦā§° āĻĒā§ā§°āĻļā§āύ

Q1. Name the device that converts electrical energy into mechanical energy.


Ans: Electric motor āωāĻ¤ā§āϤ⧰: āĻŦ⧈āĻĻā§āϝ⧁āϤāĻŋāĻ• āĻŽā§‹āϟ⧰


Q2. What happens to the magnetic field if current in a conductor is increased ?Ans: Magnetic field strength increases. āωāĻ¤ā§āϤ⧰: āϧāĻžā§°āĻž āĻŦ⧃āĻĻā§āϧāĻŋ āĻĒāĻžāϞ⧇ āϚ⧁āĻŽā§āĻŦāϕ⧀āϝāĻŧ āĻ•ā§āώ⧇āĻ¤ā§ā§°ā§° āĻļāĻ•ā§āϤāĻŋāĻ“ āĻŦ⧃āĻĻā§āϧāĻŋ āĻĒāĻžāϝāĻŧāĨ¤

Q3. Write the relation between current and charge.

Ans: Q = I × t āωāĻ¤ā§āϤ⧰: Q = I × t (āφāϧāĻžāύ = āϧāĻžā§°āĻž × āϏāĻŽāϝāĻŧ)

Q4. Which type of magnet is used in an electric bell?

Ans: Electromagnet āωāĻ¤ā§āϤ⧰: āχāϞ⧇āĻ•ā§āĻŸā§ā§°ā§‹āĻŽā§‡āĻ—āύ⧇āϟ

 

2 Marks Questions : ⧍ āύāĻŽā§āĻŦā§° āĻĒā§ā§°āĻļā§āύ

 

Q5. Why does a compass needle deflect when placed near a current carrying conductor ?

Ans: A current carrying conductor produces a magnetic field around it. This magnetic field interacts with the magnetic field of the compass needle, causing it to deflect.


āωāĻ¤ā§āϤ⧰: āϧāĻžā§°āĻž āĻŦāĻšāύ āϕ⧰āĻž āĻĒā§°āĻŋāĻŦāĻžāĻšāϕ⧰ āϚāĻžā§°āĻŋāĻ“āĻĢāĻžāϞ⧇ āĻāϟāĻž āϚ⧁āĻŽā§āĻŦāϕ⧀āϝāĻŧ āĻ•ā§āώ⧇āĻ¤ā§ā§° āϏ⧃āĻˇā§āϟāĻŋ āĻšāϝāĻŧāĨ¤ āĻāχ āĻ•ā§āώ⧇āĻ¤ā§ā§°āχ āĻ•āĻŽā§āĻĒāĻžāϛ⧰ āϚ⧁āĻŽā§āĻŦāϕ⧀āϝāĻŧ āĻ•ā§āώ⧇āĻ¤ā§ā§°ā§° āϏ⧈āϤ⧇ āĻĒāĻžā§°āĻ¸ā§āĻĒā§°āĻŋāĻ• āĻĒā§ā§°āĻ­āĻžā§ą āĻĒ⧇āϞāĻžāχ āϏ⧂āρāϚāĻŸā§‹āĻ• āĻŦ⧇āρāĻ•āĻž āϕ⧰⧇āĨ¤


Q6. Write two differences between an electromagnet and a permanent magnet.

Ans: 1. Electromagnet is temporary; permanent magnet is permanent. āχāϞ⧇āĻ•ā§āĻŸā§ā§°ā§‹āĻŽā§‡āĻ—āύ⧇āϟ āĻ…āĻ¸ā§āĻĨāĻžāϝāĻŧā§€; āĻ¸ā§āĻĨāĻžāϝāĻŧā§€ āϚ⧁āĻŽā§āĻŦāĻ• āĻ¸ā§āĻĨāĻžāϝāĻŧā§€āĨ¤


2. Strength of an electromagnet can be changed; permanent magnet strength cannot be changed. āχāϞ⧇āĻ•ā§āĻŸā§ā§°ā§‹āĻŽā§‡āĻ—āύ⧇āϟ⧰ āĻļāĻ•ā§āϤāĻŋ āϏāϞāύāĻŋ āϕ⧰āĻŋāĻŦ āĻĒāĻžā§°āĻŋ; āĻ¸ā§āĻĨāĻžāϝāĻŧā§€ āϚ⧁āĻŽā§āĻŦāϕ⧰ āĻļāĻ•ā§āϤāĻŋ āϏāϞāύāĻŋ āϕ⧰āĻŋāĻŦ āĻ¨ā§‹ā§ąāĻžā§°āĻŋāĨ¤


Q7. State any two characteristics of magnetic field lines.

Ans: 1. Magnetic field lines form closed loops. āϚ⧁āĻŽā§āĻŦāϕ⧀āϝāĻŧ āĻ•ā§āώ⧇āĻ¤ā§ā§°ā§° ⧰⧇āĻ–āĻžāϏāĻŽā§‚āĻš āĻŦāĻ¨ā§āϧ āϞ⧁āĻĒ āĻ—āĻ āύ āϕ⧰⧇āĨ¤


2. They never intersect each other. āĻāχ ⧰⧇āĻ–āĻžāϏāĻŽā§‚āĻš āϕ⧇āϤāĻŋāϝāĻŧāĻžāĻ“ āĻāϜāύ⧇ āφāύāϜāύāĻ• āϛ⧇āĻĻ āύāϕ⧰⧇āĨ¤


Exam Tip : āĻĒā§°ā§€āĻ•ā§āώāĻžā§° āϟāĻŋāĻĒāĻ›

  1. Learn all 1-mark questions - they are scoring and often repeated. āϏāĻ•āϞ⧋ ā§§ āύāĻŽā§āĻŦā§° āĻĒā§ā§°āĻļā§āύ āĻĒāĻĸāĻŧāĻŋ ā§°āĻžāĻ–āĻž — āϏāĻšāĻœā§‡ āύāĻŽā§āĻŦā§° āĻĒā§‹ā§ąāĻž āϝāĻžāϝāĻŧāĨ¤

  2. Practice diagrams for motor, generator, and magnetic field lines. āĻŽā§‹āϟ⧰, āĻœā§‡āύ⧇⧰⧇āϟ⧰ āφ⧰⧁ āϚ⧁āĻŽā§āĻŦāϕ⧀āϝāĻŧ āĻ•ā§āώ⧇āĻ¤ā§ā§°ā§° āϚāĻŋāĻ¤ā§ā§° āĻ…āĻ­ā§āϝāĻžāϏ āϕ⧰āĻžāĨ¤

  3. Remember formulas like Q = I × t. Q = I × t āĻĻ⧰⧇ āϏ⧂āĻ¤ā§ā§°āϏāĻŽā§‚āĻš āĻŽāύāϤ ā§°āĻžāĻ–āĻžāĨ¤




Assertion - Reason Questions


Assertion–Reason āĻĒā§ā§°āĻļā§āύ














 













Choose the correct option:
A: Both Assertion and Reason are true, and Reason is the correct explanation.
B: Both are true, but Reason is not the correct explanation.
C: Assertion is true, Reason is false.
D: Assertion is false, Reason is true.


Q1. Assertion: A current carrying conductor produces a magnetic field.
Reason: Moving electric charges create magnetic effects.

Ans: A. āĻ•āĻžā§°āĻŖ āϚāϞāĻ¨ā§āϤ āφāϧāĻžāύ⧇āχ āϚ⧁āĻŽā§āĻŦāϕ⧀āϝāĻŧ āĻ•ā§āώ⧇āĻ¤ā§ā§° āϏ⧃āĻˇā§āϟāĻŋ āϕ⧰⧇āĨ¤


Q2. Assertion: Magnetic field lines never intersect.
Reason: At one point, the magnetic field has only one direction.

Ans: A. āĻāϟāĻž āĻŦāĻŋāĻ¨ā§āĻĻ⧁āϤ āĻ•ā§āώ⧇āĻ¤ā§ā§°ā§° āĻ•ā§‡ā§ąāϞ āĻāϟāĻž āĻĻāĻŋāĻļ āĻĨāĻžāϕ⧇āĨ¤


Q3. Assertion: An electromagnet is preferred over a permanent magnet in cranes.
Reason: Its strength can be controlled by changing current.

Ans: A. āϧāĻžā§°āĻž āϏāϞāύāĻŋ āϕ⧰āĻŋ āĻļāĻ•ā§āϤāĻŋ āύāĻŋāϝāĻŧāĻ¨ā§āĻ¤ā§ā§°āĻŖ āϕ⧰āĻŋāĻŦ āĻĒāĻžā§°āĻŋāĨ¤


Case-Based PYQs : Case-based āĻĒā§ā§°āĻļā§āύ


Case: Ravi observed that when current flows through a wire placed near a compass, the needle deflects.


Q1. What does this experiment prove ?
Magnetic effect of electric current. āĻŦāĻŋāĻĻā§āĻ¯ā§ā§Ž āϧāĻžā§°āĻžā§° āϚ⧁āĻŽā§āĻŦāϕ⧀āϝāĻŧ āĻĒā§ā§°āĻ­āĻžā§ąāĨ¤


Q2. Name the rule used to find the direction of magnetic field.
Right Hand Thumb Rule. āϏ⧋āρ āĻšāĻžāϤ⧰ āĻŦ⧁āĻĸāĻŧāĻž āφāϙ⧁āϞāĻŋā§° āύāĻŋāϝāĻŧāĻŽ


Q3. What will happen if the current increases ?
Magnetic field becomes stronger. āϚ⧁āĻŽā§āĻŦāϕ⧀āϝāĻŧ āĻ•ā§āώ⧇āĻ¤ā§ā§° āĻŦ⧇āĻ›āĻŋ āĻļāĻ•ā§āϤāĻŋāĻļāĻžāϞ⧀ āĻš’āĻŦāĨ¤


5 Mark Expected Questions : āϏāĻŽā§āĻ­āĻžāĻŦā§āϝ ā§Ģ āύāĻŽā§āĻŦā§° āĻĒā§ā§°āĻļā§āύ


Q1. Explain Fleming’s Left Hand Rule with diagram description.

Ans: Stretch the thumb, forefinger, and middle finger of the left hand mutually perpendicular.



  • Forefinger → Magnetic field

  • Middle finger → Current

  • Thumb → Force / Motion


Use: Electric motor. āĻŦā§āĻ¯ā§ąāĻšāĻžā§°: āĻŦ⧈āĻĻā§āϝ⧁āϤāĻŋāĻ• āĻŽā§‹āϟ⧰


Q2. Differentiate between Electric Motor and Electric Generator.

Electric Motor: Converts electrical → mechanical energy. āĻŦ⧈āĻĻā§āϝ⧁āϤāĻŋāĻ• āĻļāĻ•ā§āϤāĻŋāĻ• āϝāĻžāĻ¨ā§āĻ¤ā§ā§°āĻŋāĻ• āĻļāĻ•ā§āϤāĻŋāϤ ā§°ā§‚āĻĒāĻžāĻ¨ā§āϤ⧰ āϕ⧰⧇āĨ¤


Electric Generator: Converts mechanical → electrical energy. āϝāĻžāĻ¨ā§āĻ¤ā§ā§°āĻŋāĻ• āĻļāĻ•ā§āϤāĻŋāĻ• āĻŦ⧈āĻĻā§āϝ⧁āϤāĻŋāĻ• āĻļāĻ•ā§āϤāĻŋāϤ ā§°ā§‚āĻĒāĻžāĻ¨ā§āϤ⧰ āϕ⧰⧇āĨ¤


Motor uses Fleming’s Left Hand Rule. Generator uses Fleming’s Right Hand Rule


MCQs For Quick Revision : āĻĻā§ā§°ā§āϤ āĻĒ⧁āύ⧰āĻžāĻŦ⧃āĻ¤ā§āϤāĻŋā§° āĻŦāĻžāĻŦ⧇ MCQ

Q1. SI unit of magnetic field is - Tesla / Ampere / Volt / Ohm
Ans: Tesla

Q2. Device used to lift scrap iron is - Motor / Electromagnet / Generator / Battery
Ans: Electromagnet

Q3. Magnetic field around a straight conductor is - Circular / Straight / Parallel / Random
Ans: Circular

Q4. Electric motor works on - Heating effect / Chemical effect / Magnetic effect / Optical effect
Ans: Magnetic effect

Q5. Formula for electric charge is —
V = IR | Q = I × t | P = VI | F = ma
Ans: Q = I × t

Ultra-Short Notes (Last Day Revision) : āĻļ⧇āώ āĻĻāĻŋāύ⧰ āĻĻā§ā§°ā§āϤ āύ⧋āϟ

Moving charges produce magnetic field. āϚāϞāĻ¨ā§āϤ āφāϧāĻžāύ⧇āχ āϚ⧁āĻŽā§āĻŦāϕ⧀āϝāĻŧ āĻ•ā§āώ⧇āĻ¤ā§ā§° āϏ⧃āĻˇā§āϟāĻŋ āϕ⧰⧇āĨ¤


Field lines form closed loops. āĻ•ā§āώ⧇āĻ¤ā§ā§°ā§° ⧰⧇āĻ–āĻžāĻŦā§‹ā§° āĻŦāĻ¨ā§āϧ āϞ⧁āĻĒāĨ¤


Motor → Electrical to Mechanical Motor → āĻŦ⧈āĻĻā§āϝ⧁āϤāĻŋāĻ• → āϝāĻžāĻ¨ā§āĻ¤ā§ā§°āĻŋāĻ•


Generator → Mechanical to Electrical Generator → āϝāĻžāĻ¨ā§āĻ¤ā§ā§°āĻŋāĻ• → āĻŦ⧈āĻĻā§āϝ⧁āϤāĻŋāĻ•


Fleming Left → Motor
Fleming Right → Generator


Electromagnet = Temporary magnet
āχāϞ⧇āĻ•ā§āĻŸā§ā§°ā§‹āĻŽā§‡āĻ—āύ⧇āϟ = āĻ…āĻ¸ā§āĻĨāĻžāϝāĻŧā§€ āϚ⧁āĻŽā§āĻŦāĻ•