Advertisements
Advertisements
प्रश्न
The diagram shows a coil wound around a U shape soft iron bar AB.
1) What is the polarity induced at the ends A and B when the switch is pressed?
2) Suggest one way to strengthen the magnetic field in the electromagnet
3) What will be the polarities at A & B if the direction of current is reversed in the circuit?
Advertisements
उत्तर
1) A - South, B - North
2) Increasing the number of turns of coils, increasing current.
3) A-North, B - South
APPEARS IN
संबंधित प्रश्न
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
(a) The no. of turns in the secondary is doubled?
(b) The part X of the transformer is removed?
( c) The core of the transformer is made out of copper?
(d ) The A.C. supply is replaced by D.C.?
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.
State the two properties of the magnetic lines of force around a circular coil.
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?
State the energy change that takes’place in a D. C. motor.
What is dynomo (a.c. generator)? State the principle on which it works.
State important properties (or characteristics) of magnetic lines of force around a straight conductor.
Which magnet will you use?
Iron is to be separated from trash.
