Advertisements
Advertisements
Question
List some of the practical applications of an electromagnet.
Advertisements
Solution
Electromagnets are used to lift heavy loads of scrap iron etc., to separate magnetic substances from non-magnetic ones and in devices like the electric bell, telegraphs, telephones, loud speakers, etc.
RELATED QUESTIONS
Explain different ways to induce current in a coil.
It is desired to measure the magnitude of field between the poles of a powerful loud speaker magnet. A small flat search coil of area 2 cm2 with 25 closely wound turns, is positioned normal to the field direction, and then quickly snatched out of the field region. Equivalently, one can give it a quick 90° turn to bring its plane parallel to the field direction. The total charge flown in the coil (measured by a ballistic galvanometer connected to coil) is 7.5 mC. The combined resistance of the coil and the galvanometer is 0.50 Ω. Estimate the field strength of magnet.
In which of the following case does the electromagnetic induction occur?
The current is stopped in a wire held near a loop of wire .
A conducting square loop of side l and resistance R moves in its plane with a uniform velocity v perpendicular to one of its sides. A uniform and constant magnetic field Bexists along the perpendicular to the plane of the loop as shown in figure. The current induced in the loop is _____________ .

The diagram shows a rectangular coil ABCD, suspended freely between the concave pole pieces of a permanent horseshoe magnet, such that the plane of the coil is parallel to the magnetic field.

- State your observation when the current is switched on.
- Give an explanation for your observation in (i).
- State the rule, which will help you to find the motion of rotation of the coil.
- In which position will the coil ultimately come to rest?
- State four ways of increasing the magnitude of force acting on the coil.
Choose the correct option:
A conductor rod of length (l) is moving with velocity (v) in a direction normal to a uniform magnetic field (B). What will be the magnitude of induced emf produced between the ends of the moving conductor?
Show that Lenz’s law is in accordance with the law of conservation of energy.
The instrument that use to defect electric current in the circuit is known as ____________.
Induced current flows through a coil ______.
A galvanometer is an instrument that can detect the presence of a current in a circuit.
