Advertisements
Advertisements
Question
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.
D.C. motor ______.
Advertisements
Solution
D.C. motor core- soft iron, magnet - steel
APPEARS IN
RELATED QUESTIONS
A horizontal straight wire 10 m long extending from east to west is falling with a speed of 5.0 m s−1, at right angles to the horizontal component of the earth’s magnetic field, 0.30 × 10−4 Wb m−2.
- What is the instantaneous value of the emf induced in the wire?
- What is the direction of the emf?
- Which end of the wire is at the higher electrical potential?
Name two devices in which electromagnets are used and two devices where permanent magnets are used.
Can a transformer work when it is connected to a D.C. source? Give a reason.
Using Ampere's law, obtain an expression for the magnetic induction near a current-carrying straight infinitely long wire.
Write the two names in the following diagram.
Right hand thumb rule.
Write the two names in the following diagram.
Fleming’s right hand rule.
An induced current of 2.5 mA flows through a single conductor of resistance 100 Ω. Find out the rate at which the magnetic flux is cut by the conductor.
If the sun radiates energy at the rate of 3.6 × 1033 ergs/sec the rate at which the sun is loosing mass is given by ______.
Name some equipment that uses electromagnetism for functioning.
Which of the following instruments works by electromagnetic induction?
