Why Does a Magnet Attract Iron ? :: āĻā§āĻŽā§āĻŦāĻā§ āĻ˛ā§āĻšāĻž āĻāĻŋāĻ¯āĻŧ āĻāĻā§°ā§āĻˇāĻŖ āĻā§°ā§ ?
Iron contains tiny magnetic regions called domains. In ordinary iron, these domains point in different directions. A magnet creates a magnetic field around it. This magnetic field causes many iron domains to align in the same direction. When the domains align, the iron itself becomes temporarily magnetic. As a result, the iron is pulled toward the magnet.
āĻ˛ā§āĻšāĻžā§° āĻāĻŋāĻ¤ā§°āĻ¤ āĻ
āĻ¤āĻŋ āĻ¸ā§°ā§ āĻā§āĻŽā§āĻŦāĻā§āĻ¯āĻŧ āĻ
āĻāĻļ āĻĨāĻžāĻā§, āĻ¯āĻžāĻ āĻĄ’āĻŽā§āĻāĻ¨ (Domains) āĻŦā§āĻ˛āĻŋ āĻā§ā§ąāĻž āĻšāĻ¯āĻŧāĨ¤ āĻ¸āĻžāĻ§āĻžā§°āĻŖ āĻ˛ā§āĻšāĻžāĻ¤ āĻāĻ āĻĄ’āĻŽā§āĻāĻ¨āĻŦā§ā§° āĻŦāĻŋāĻāĻŋāĻ¨ā§āĻ¨ āĻĻāĻŋāĻļāĻ¤ āĻĨāĻžāĻā§āĨ¤ āĻāĻāĻž āĻā§āĻŽā§āĻŦāĻā§ āĻ¨āĻŋāĻā§° āĻāĻžā§°āĻŋāĻāĻĢāĻžāĻ˛ā§ āĻā§āĻŽā§āĻŦāĻā§āĻ¯āĻŧ āĻā§āĻˇā§āĻ¤ā§ā§° (Magnetic Field) āĻ¸ā§āĻˇā§āĻāĻŋ āĻā§°ā§āĨ¤ āĻāĻ āĻā§āĻŽā§āĻŦāĻā§āĻ¯āĻŧ āĻā§āĻˇā§āĻ¤ā§ā§°āĻ āĻ˛ā§āĻšāĻžā§° āĻŦāĻšā§ āĻĄ’āĻŽā§āĻāĻ¨āĻ āĻāĻā§ āĻĻāĻŋāĻļāĻ¤ āĻ¸āĻāĻžāĻ āĻ¤ā§āĻ˛ā§ āĻĄ’āĻŽā§āĻāĻ¨āĻŦā§ā§° āĻāĻā§ āĻĻāĻŋāĻļāĻ¤ āĻ¸āĻžāĻāĻŋāĻ˛ā§ āĻ˛ā§āĻšāĻžāĻā§ āĻ¨āĻŋāĻā§āĻ āĻ¸āĻžāĻŽāĻ¯āĻŧāĻŋāĻāĻāĻžā§ąā§ āĻā§āĻŽā§āĻŦāĻā§āĻ¯āĻŧ āĻšā§ āĻĒā§°ā§āĨ¤ āĻĢāĻ˛āĻ¤ āĻ˛ā§āĻšāĻžāĻā§ āĻā§āĻŽā§āĻŦāĻā§° āĻĢāĻžāĻ˛ā§ āĻāĻžāĻ¨āĻŋ āĻ¨āĻŋāĻ¯āĻŧā§ āĻ¯āĻžāĻ¯āĻŧāĨ¤
Key Point / āĻŽā§āĻā§āĻ¯ āĻāĻĨāĻž : A magnet attracts iron because its magnetic field aligns the magnetic domains inside the iron. (āĻā§āĻŽā§āĻŦāĻā§° āĻā§āĻŽā§āĻŦāĻā§āĻ¯āĻŧ āĻā§āĻˇā§āĻ¤ā§ā§°āĻ āĻ˛ā§āĻšāĻžā§° āĻāĻŋāĻ¤ā§°ā§° āĻĄ’āĻŽā§āĻāĻ¨āĻŦā§ā§° āĻāĻā§ āĻĻāĻŋāĻļāĻ¤ āĻ¸āĻāĻžāĻ āĻ¤ā§āĻ˛ā§, āĻ¸ā§āĻāĻŦāĻžāĻŦā§āĻ āĻā§āĻŽā§āĻŦāĻā§ āĻ˛ā§āĻšāĻžāĻ āĻāĻā§°ā§āĻˇāĻŖ āĻā§°ā§āĨ¤)
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MCQ:
Q1. Why is iron attracted to a magnet ? (āĻ˛ā§āĻšāĻž āĻā§āĻŽā§āĻŦāĻā§° āĻĢāĻžāĻ˛ā§ āĻāĻŋāĻ¯āĻŧ āĻāĻā§°ā§āĻˇāĻŋāĻ¤ āĻšāĻ¯āĻŧ ?)
A. Iron becomes hot B. Iron melts C. Magnetic domains align D. Iron loses weight
Ans / āĻāĻ¤ā§āĻ¤ā§°: C. Magnetic domains align
Explanation / āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž: A magnet aligns the tiny magnetic domains inside iron. (āĻā§āĻŽā§āĻŦāĻā§ āĻ˛ā§āĻšāĻžā§° āĻāĻŋāĻ¤ā§°ā§° āĻ¸ā§°ā§ āĻĄ’āĻŽā§āĻāĻ¨āĻŦā§ā§° āĻāĻā§ āĻĻāĻŋāĻļāĻ¤ āĻ¸āĻžāĻāĻžāĻ¯āĻŧāĨ¤)
Q2. What are tiny magnetic regions inside iron called ? (āĻ˛ā§āĻšāĻžā§° āĻāĻŋāĻ¤ā§°ā§° āĻ¸ā§°ā§ āĻā§āĻŽā§āĻŦāĻā§āĻ¯āĻŧ āĻ
āĻāĻļāĻŦā§ā§°āĻ āĻāĻŋ āĻā§ā§ąāĻž āĻšāĻ¯āĻŧ ?)
A. Atoms B. Domains C. Circuits D. Charges
Ans / āĻāĻ¤ā§āĻ¤ā§°: B. Domains
Explanation / āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž: The tiny magnetic parts inside iron are called domains. (āĻ˛ā§āĻšāĻžā§° āĻāĻŋāĻ¤ā§°ā§° āĻ¸ā§°ā§ āĻā§āĻŽā§āĻŦāĻā§āĻ¯āĻŧ āĻ
āĻāĻļāĻŦā§ā§°āĻ āĻĄ’āĻŽā§āĻāĻ¨ āĻŦā§āĻ˛āĻŋ āĻā§ā§ąāĻž āĻšāĻ¯āĻŧāĨ¤)
Q3. In ordinary iron, domains point in ______ directions. (āĻ¸āĻžāĻ§āĻžā§°āĻŖ āĻ˛ā§āĻšāĻžāĻ¤ āĻĄ’āĻŽā§āĻāĻ¨āĻŦā§ā§° ______ āĻĻāĻŋāĻļāĻ¤ āĻĨāĻžāĻā§āĨ¤)
A. same B. upward C. different D. downward
Ans / āĻāĻ¤ā§āĻ¤ā§°: C. different
Explanation / āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž: Normally, domains point in different directions. (āĻ¸āĻžāĻ§āĻžā§°āĻŖāĻ¤ā§ āĻĄ’āĻŽā§āĻāĻ¨āĻŦā§ā§° āĻŦāĻŋāĻāĻŋāĻ¨ā§āĻ¨ āĻĻāĻŋāĻļāĻ¤ āĻĨāĻžāĻā§āĨ¤)
Q4. What does a magnet create around it ? (āĻā§āĻŽā§āĻŦāĻā§ āĻ¨āĻŋāĻā§° āĻāĻžā§°āĻŋāĻāĻĢāĻžāĻ˛ā§ āĻāĻŋ āĻ¸ā§āĻˇā§āĻāĻŋ āĻā§°ā§ ?)
A. Heat field B. Electric wire C. Magnetic field D. Water wave
Ans / āĻāĻ¤ā§āĻ¤ā§°: C. Magnetic field
Explanation / āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž: A magnet creates a magnetic field around itself. (āĻā§āĻŽā§āĻŦāĻā§ āĻ¨āĻŋāĻā§° āĻāĻžā§°āĻŋāĻāĻĢāĻžāĻ˛ā§ āĻā§āĻŽā§āĻŦāĻā§āĻ¯āĻŧ āĻā§āĻˇā§āĻ¤ā§ā§° āĻ¸ā§āĻˇā§āĻāĻŋ āĻā§°ā§āĨ¤)
Q5. What happens when iron domains align ? (āĻ˛ā§āĻšāĻžā§° āĻĄ’āĻŽā§āĻāĻ¨āĻŦā§ā§° āĻāĻā§ āĻĻāĻŋāĻļāĻ¤ āĻ¸āĻžāĻāĻŋāĻ˛ā§ āĻāĻŋ āĻšāĻ¯āĻŧ ?)
A. Iron breaks B. Iron becomes magnetic C. Iron cools down D. Iron disappears
Ans / āĻāĻ¤ā§āĻ¤ā§°: B. Iron becomes magnetic
Explanation / āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž: Aligned domains make iron magnetic. (āĻĄ’āĻŽā§āĻāĻ¨āĻŦā§ā§° āĻāĻā§ āĻĻāĻŋāĻļāĻ¤ āĻ¸āĻžāĻāĻŋāĻ˛ā§ āĻ˛ā§āĻšāĻž āĻā§āĻŽā§āĻŦāĻā§āĻ¯āĻŧ āĻšāĻ¯āĻŧāĨ¤)
Q6. Which material is strongly attracted by a magnet ? (āĻ¤āĻ˛ā§° āĻā§āĻ¨āĻā§ āĻĒāĻĻāĻžā§°ā§āĻĨ āĻā§āĻŽā§āĻŦāĻā§ āĻŦā§āĻāĻŋ āĻāĻā§°ā§āĻˇāĻŖ āĻā§°ā§ ?)
A. Wood B. Plastic C. Iron D. Rubber
Ans / āĻāĻ¤ā§āĻ¤ā§°: C. Iron
Explanation / āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž: Iron is a magnetic material. (āĻ˛ā§āĻšāĻž āĻāĻāĻž āĻā§āĻŽā§āĻŦāĻā§āĻ¯āĻŧ āĻĒāĻĻāĻžā§°ā§āĻĨāĨ¤)
Q7. A magnet attracts iron mainly because of its ______. (āĻā§āĻŽā§āĻŦāĻā§ āĻ˛ā§āĻšāĻžāĻ āĻŽā§āĻ˛āĻ¤āĻ āĻ¨āĻŋāĻā§° ______ ā§° āĻŦāĻžāĻŦā§ āĻāĻā§°ā§āĻˇāĻŖ āĻā§°ā§āĨ¤)
A. color B. weight C. magnetic field D. shape
Ans / āĻāĻ¤ā§āĻ¤ā§°: C. magnetic field
Explanation / āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž: The magnetic field aligns iron domains. (āĻā§āĻŽā§āĻŦāĻā§āĻ¯āĻŧ āĻā§āĻˇā§āĻ¤ā§ā§°āĻ āĻ˛ā§āĻšāĻžā§° āĻĄ’āĻŽā§āĻāĻ¨āĻŦā§ā§° āĻ¸āĻāĻžāĻ¯āĻŧāĨ¤)
Q8. When domains point randomly, iron is ______. (āĻĄ’āĻŽā§āĻāĻ¨āĻŦā§ā§° āĻāĻ˛ā§āĻŽā§āĻ˛ā§ āĻĻāĻŋāĻļāĻ¤ āĻĨāĻžāĻāĻŋāĻ˛ā§ āĻ˛ā§āĻšāĻž ______ āĻšāĻ¯āĻŧāĨ¤)
A. magnetic B. non-magnetic C. liquid D. hot
Ans / āĻāĻ¤ā§āĻ¤ā§°: B. non-magnetic
Explanation / āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž: Random domains cancel each other’s effect. (āĻāĻ˛ā§āĻŽā§āĻ˛ā§ āĻĄ’āĻŽā§āĻāĻ¨āĻŦā§ā§°ā§ āĻāĻā§ āĻāĻ¨ā§° āĻĒā§ā§°āĻāĻžā§ą āĻŦāĻžāĻ¤āĻŋāĻ˛ āĻā§°ā§āĨ¤)