| Message |
|
|
|
Virtual object is(are) a point of convergance of rays.
|
|
|
|
a).Position of the point of convergence from the convex lens of focal length 20 cm = (12X20)/(12+20)= 7.5 cm.
b). Position of convergance from the concave lens of 12 cm = (12X -16)/(12-16) = 48 cm
|
|
|
|
I think electric field lines are not always continues. For example if place a conductor in an electric field the field lines break of at the surfaces of the conductor leaving a field free region with in the conductor.
But magnetic field lines are continues. That is because the sources of magnetic fields are dipoles.
|
|
|
|
|
I think, Paper does not melt because its ignition temperature is less than its melting point. It ignites before it melts.
|
|
|
|
|
Electric field in side the hollow sphere will be zero if the charges are distributed uniformly over the surface.
|
|
|
|
|
post office box is an arrangement to determine resistances quite accurately. It works on the principle of Wheatstones bridge.
|
|
|
|
R1 + 10 = R2
R1/R2 = 2/3
solving the equation will give R1 = 20 ohm
|
|
|
|
|
You are right. Magnetic monopoles do not exist. There is no contradiction when we say that with in the magnet the magnetic field lines are directed from south pole to north pole. To make the magnetic lines continues, outside the magnet they are directed from north pole to south pole.
|
|
|
|
|
When Huygen proposed the wave theory of light it was considered as a mechanical wave because the concept of electromagnetic waves was not yet developed. Since all the mechanical waves require a medium of propogation a hypothetical medium was proposed. This hypothetical medium is known as luminiferous ether. Later Michelson-Morley experiment conclusively proved that such medium does not exist.
|
|
|
|
|
D) with s1 and S3 closed V1=30 V and v2 = 20 V.
|
|
|
|
|
3. at equatorial points and axial points the electric field will be parallel to the line joininng the two charges.
|
|
|
|
|
mark the two end terminals as A and B. Check the plates of each capacitor and you will find that if one plate is connected to A the other will be connected to B. It implies that all the capcitors share the same potential difference and hence they are parallel
|
|
|
|
|
|
I think it is because there are are two different types of poles. Suppose you only one type of pole then thre will be one kind of interaction. But since there are two kinds of poles we observe two kinds of interaction; attraction and repulsion. That is how they realized there are two different kinds of poles.
|
|
|
|
|
if the +ve plate of one of the capacitor is connected to the negative plate then the potential difference is 6 V
|
|
|
|
