Advertisements
Advertisements
Question
Write the answer in your word.
How is an electromagnet made?
Solution
For the construction of an electromagnet, we require an iron nail, a long insulated copper wire, a battery and a switch.
The long, insulated copper wire is first wound on the iron nail. Then the two free ends of the wire are connected to the battery and the switch as shown. Now that the switch is turned on, current flows through the circuit. Due to this flow of current, the insulated copper wire and iron nail act as an electromagnet. Now, if iron pins are brought close to this set-up, they stick to the iron nail.
As soon as the current stops flowing in the circuit, the iron nail loses magnetism and the pins fall off.
Case: Switch open
Case: Switch close
RELATED QUESTIONS
principle of an electric motor ?
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 ______.
Complete the following sentence :
On reserving the direction of current in a wire, the magnetic field produced by it gets _____.
The magnetic flux through a coil having 100 turns decreases from 5 milli weber to zero in 5 second. Calculate the e.m.f. induced in the coil.
Answer the following in short.
Name a few common appliances that use electromagnets.
A straight current-carrying conductor is kept in a magnetic field. It Experiences a force. State three factors on which the magnitude of force Experienced by the conductor depends. Under what condition will the conductor Experience no force?
How does a magnetic field set up by a solenoid change when a soft iron core is inserted inside solenoid?
State the factors that can increase the speed of rotation of the coil in a D.C. motor.
State the principle of a D. C. motor.
State important properties (or characteristics) of magnetic lines of force around a straight conductor.