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प्रश्न
State the position of armature coil relative to the direction of magnetic field, in a D. C. motor when the deflecting couple acting an the coil is maximum.
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उत्तर
The deflecting couple acting on the coil is maximum when the plane of the coil is parallel to the direction of magnetic field.
संबंधित प्रश्न
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.
Name the type of transformer shown in Fig. What changes will you observe regarding the brightness of the lamp, if
- the number of turns in the secondary is doubled? Explain.
- the part X of the transformer is removed?
- the core of the transformer is made out of copper?
- the A.C. supply is replaced by D.C.?
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.
Electric bell ______.
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 the two properties of the magnetic lines of force around a circular coil.
State the purpose of the iron core.
State the factors that can increase the speed of rotation of the coil in a D.C. motor.
State the energy change that takes’place in a D. C. motor.
Write the answer in your words.
How is an electromagnet made?
