1 explain the refraction of light through a triangular glass prism 2. what is a solenoid discuss the magnetic field due to a current crying solenoid 3. describe the experiment showing that magnetic field is produced due to electric current
Answers
A coil with many circular close turns of insulated copper wire (like a cylinder as shown above) is a solenoid. One end of such a solenoid behaves like the north pole and the other as a south pole. Therefore magnetic field due to current in the solenoid is similar to a bar magnet.
1) ∙ABC is prism with base BC
∙ PE is incident ray on surface AB. It makes ∠PEN
with the normal NE. This angle is angle of incidence.
∙After entering the prism, the light ray bends towards normal.
In this case, EF is refracted ray. ∠N
′
EF is angle of refraction.
∙Once the refracted ray emerges from prism into air, it bends away from normal. In this figure, FS is emergent ray, ∠SFM is angle of emergence.
Angle of Deviation: The angle between incident ray and emergent
ray is called angle of deviation. Here, ∠SGH is angle of deviation or ∠D
2) When an electric current flow through a solenoid,magnetic field is set up around solenoid similar to that of a bar magnet. One end of a solenoid act as a north pole and other as south pole. Magnetic field is represented by straight magnetic field lines parallel and very close to each other.
3) We take a thick insulated copper wire and fix it in such a way that the portion AB of the wire is in the north-south direction as shown in fig. A plotting compass M is placed under the wire AB. The two ends of the wire are connected to a battery through a switch. When no current is flowing in the wire AB, the compass needle is parallel to the wire AB and points in the usual north-south direction. When current is passed through wire AB by closing the switch, we find that the compass needle is deflected from its north-south position. On opening the switch, the compass needle returns to its original position.
Thus, the deflection of compass needle by the current carrying wire shows that magnetic field is associated with an electric current.
