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e) What is a magnetic compass? How is it usefultshow that magnetism in a bar magnet is strongest at its pokes) How can you magnetise an iron needle? |
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Answer» Themagnetic compasswas animportantadvance in navigation because it allowed mariners to determine their direction even if clouds obscured their usual astronomical cues such as the North Star. It uses amagneticneedle that can turn freely so that it always points to the north pole of the Earth'smagneticfield. 2. The magneticfield of abar magnet is strongestat eitherpoleofthe magnet. It is equallystrong at thenorthpole when compared withthesouthpole. Theforce is weaker inthemiddle ofthe magnetand halfway betweenthe poleandthecenter. 3. Stroke aneedlewith the north end of a bar magnet around 50 times, lifting between strokes. Stroking from tail to tip pulls theneedle's ironatoms into alignment, turning theneedleinto a weak temporary magnet. Attach themagnetised needleto your circle of cork with tack and carefully place it into a dish of water. |
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