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प्रश्न
A straight wire is held vertical and current is passed in it in the upward direction. A compass needle is kept near the wire in north of it. How is the needle deflected? What is the change in the deflection of the needle if the current in wire is reversed?
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उत्तर
When the current in the wire is upwards, the needle will deflect with its north pole towards west.
If the current in the wire is reversed, the north pole of the needle will deflect towards east.
संबंधित प्रश्न
The diagram shows a coil wound around a U shape soft iron bar AB.
1) What is the polarity induced at the ends A and B when the switch is pressed?
2) Suggest one way to strengthen the magnetic field in the electromagnet
3) What will be the polarities at A & B if the direction of current is reversed in the circuit?
How will you make an iron bar electromagnet? Draw a diagram showing the polarities of the electromagnet?
Name two factors on which the strength of magnetic field of an electromagnet depends and state how does it depend on the factors stated by you.
State two differences between an electromagnet and a permanent magnet.
Answer the following in short.
Name a few common appliances that use electromagnets.
State two factors on which the strength of induced e. m.f. depends.
What is a permanent magnet? Give one use of it.
State the position of armature coil relative to the direction of magnetic field, in a D. C. motor when the deflecting couple acting and the coil is minimum.
State important properties (or characteristics) of magnetic lines of force around a straight conductor.
State the function of a split ring in D.C. motor.
