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प्रश्न
How does a magnetic field set up by a solenoid change when strength of current in the solenoid is decreased?
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उत्तर
By decreasing the current flowing in the solenoid, the intensity of magnetic field decreases.
संबंधित प्रश्न
How will you make an iron bar electromagnet? Draw a diagram showing the polarities of the electromagnet?
State two differences between an electromagnet and a permanent magnet.
Fill in the blanks by writing (i) Only soft iron, (ii) Only steel, (iii) Both soft-iron and steel for the material of core and/or magnet.
Electromagnet ______.
State two factors on which the magnitude of an induced e.m.f. in the secondary coils of a transformer depends.
State the purpose of the iron core.
Why is soft iron generally used as the core of the electromagnet?
State three factors which govern the speed of rotation of an electric motor.
State the factors that can increase the speed of rotation of the coil in a D.C. motor.
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.
The primary windings of a step-up transformer are usually made of thicker wire than the secondary. Explain.
