Magnets mein attraction aur repulsion

Do magnets milte hain to kya hota hai?

Activity 4.5 mein tum do bar magnets, A aur B, lete ho jinke poles pe nishaan hain. Magnet A ko 5 ya 6 gol pencilon pe rakha jaata hai taaki wo aasaani se ludhak sake. Phir magnet B ka ek sira, bina chhuye, magnet A ke ek sire ke paas laaya jaata hai. Phir B ka doosra sira A ke usi sire ke paas.

Kabhi magnet A magnet B ki taraf ludhakta hai, kabhi usse door. Poles tay karte hain kya hoga:

• Ulte poles kheenchte hain: ek magnet ka North pole aur doosre ka South pole ek-doosre ko kheenchte hain.
• Same poles dhakelte hain: do North poles, ya do South poles, ek-doosre ko door dhakelte hain.

Iron ki chhad ka test

Ek magnet ki jagah iron ki chhad lekar activity dohraao. Is baar iron ki chhad ke dono sire magnet ke North aur South dono poles se khinchte hain. Iron kabhi dhakela nahi jaata. Isliye:

• Kheench magnet aur iron ke beech bhi hoti hai, aur ulte poles ke beech bhi.
• Dhakka sirf do magnets ke beech hota hai.

Isiliye magnet ko repulsion ki khoobi se pehchaana ja sakta hai. Reshma isse teen ek jaisi chhadon ko chhaant sakti thi: jo do kisi sthiti mein ek-doosre ko dhakelti hain, wahi magnet hain.

Magnet aur compass ki sui

Compass ki sui bhi magnet hai, isliye wo bhi aisa hi karti hai. Activity 4.6 mein compass ko samtal rakhkar sui ko rukne diya jaata hai.

• Bar magnet ka North pole dheere se sui ke North sire ki taraf laao: sui ka North sira door jaata hai.
• Iski jagah South pole laao: sui ka North sira paas aata hai.

Activity 4.7 mein beech mein lakdi, cardboard, plastic ya kaanch ki sheet rakhne se mudna lagbhag nahi badalta: magnet ka asar non-magnetic cheezon ke aar-paar jaata hai.

Attraction aur repulsion se maza

• Race waali gaadiyan: do matchbox gaadiyon pe same poles aamne-saamne rakhkar magnet lagaao. Paas dhakelo, wo ek-doosre se door bhaagti hain.
• Tairte ring magnet: pencil pe do ring magnets same poles aamne-saamne rakhkar daalo, upar waala neeche waale ke upar tairta hai. Use ulta karo to dono chipak jaate hain.
• Phudakta mendhak: scale pe ring magnets North aur South baari-baari se lagaao, aur apne ring magnet waale mendhak ko unke upar sarkaao. Same pole pe wo upar dhakela jaata hai, ulte pole pe neeche khincha jaata hai, isliye phudakta lagta hai.
• Maglev trains magnetic dhakke aur kheench se apni patri ke zara upar tairti hain aur bahut kam ghisaav ke saath chalti hain (Extra).

Magnets ko mazboot rakhna

Bar magnets ko jodi mein, ek taraf ulte poles ke saath, beech mein lakdi ka tukda aur siron pe do soft iron ke tukde rakhkar sambhaalo. Magnets ko garam mat karo, giraao mat, hathaudi mat maaro, aur mobile phone aur remote se door rakho.

Poles kahan hote hain, ye jaanne ke liye padho magnet ke poles. Textbook ke sawaalon ke liye dekho Chapter 4 ke NCERT solutions; poore chapter ke liye Chapter 4 ke notes.