Advertisements
Advertisements
प्रश्न
Describe one experiment to demonstrate the phenomenon of electromagnetic induction.
Advertisements
उत्तर
| (a) |  |
| (b) |  |
| (c) |  |
| (d) |  |
| (e) |  |
- When the magnet is stationary there is no deflection in galvanometer. The pointer read zero. [Fig. (a)]
- When the magnet with north pole facing the solenoid is moved towards the solenoid, the galvanometer shows a deflection towards the right showing that a current flows in the solenoid in the direction as shown in [Fig. (b)]
- As the motion of magnet stops, the pointer of the galvanometer comes to the zero position [Fig. (c)]. This shows that the current in the solenoid flows as long as the magnet is moving.
- If the magnet is moved away from the solenoid, the current again flows in the solenoid, but now in a direction opposite to that shown in [Fig. (b)] and therefore the pointer of the galvanometer deflects towards left [Fig. (d)].
- If the magnet is moved away rapidly i.e. with more velocity, the extent of deflection in the galvanometer increases although the direction of deflection remains the same. It shows that more current flows now.
- (vi) If the polarity of the magnet is reversed and then the magnet is brought towards the solenoid, the current in solenoid flows in the direction opposite to that shown in Fig. (b) and so the pointer of galvanometer deflect towards left [Fig. (e)].
APPEARS IN
संबंधित प्रश्न
Electric field intensity in free space at a distance ‘r’ outside the charged conducting sphere of radius ‘R’ in terms of surface charge density ‘ a ’ is............................
(a)`sigma / in_0[R/r]^2`
(b)`in_0/sigma[R/r]^2`
(c)`R/r[sigma/in_0]^2`
(d)`R/sigma[r/in_0]^2`
In which of the following case does the electromagnetic induction occur?
A loop of wire is held near a magnet.
Show diagrammatically how an alternating emf is generated by a loop of wire rotating in a magnetic field. Write the expression for the instantaneous value of the emf induced in the rotating loop.
Draw a simple labeled diagram of a step-down transformer.
The following diagram shows a fixed coil of several turns connected to a center zero galvanometer G and a magnet NS which can move in the direction shown in the diagram.
- Describe the observation in the galvanometer if
- The magnet is moved rapidly,
- The magnet is kept still after it has moved into the coil
- The magnet is then rapidly pulled out the coil.
- How would the observation in (i) of part (a) change if a more powerful magnet is used?
The energy stored in a 50 mH inductor carrying a current of 4 A is ______
Which of the following scientist invented the rule of electromagnetic induction?
Obtain an expression for motional emf from Lorentz force.
A square coil of side 30 cm with 500 turns is kept in a uniform magnetic field of 0.4 T. The plane of the coil is inclined at an angle of 30° to the field. Calculate the magnetic flux through the coil.
Metal rings P and Q are lying in the same plane, where current I is increasing steadily. The induced current in metal rings is shown correctly in figure.
