Question

Which of the following field patterns given below is valid for electric fields as well as for magnetic fields?
A.

B.

C.

D.

Answer 1

Hint: When we say that the universe is made up of matter and atoms and molecules, the statement is not fully correct. We have to mention the existence of magnetic and electric fields. Hence the universe is made up of matter and electromagnetic fields. Magnetic field is the field produced by magnets and electric field is the field produced by charges.

Complete answer:
Magnetic field is the space around the magnet where the effect of a magnet can be felt by another magnet or iron piece. Magnetic fields can also be produced by a moving charge whose intensity can be determined by the velocity and magnitude of charge. The S.I unit of magnetic field is Tesla (T) whereas the C.G.S unit is Gauss (G).
Often we see a bar magnet having two poles i.e. north pole and south pole. Have you ever wondered why both the poles can’t exist together? This is because using gauss’s law of magnetism, it can be shown that monopoles can’t exist. Hence whenever there is a magnetic field, it must be produced by a pair of poles. Now, since two poles will always exist together, hence the magnetic field lines have to form a closed loop. They can’t exist in a non-curved state. The standard picture of a bar magnet is as shown:

Hence, option B. is correct for magnetic fields.
Now, for an electric field, which is produced by charges that can exist separately, it can’t form a closed loop, reason being the same by which magnets can form closed loops.

Hence option A. is correct for negative charge and option B. is correct for positive charge.

So, the correct answer is “Option A,B”.

Note:
It should be noted that if the electric field lines are being terminated on a charge, it is negative in nature whereas if lines are emerging from the charge, it is positive in nature. Similar is the case with magnets. Magnetic field lines emerge from the north pole of the magnet and terminate on the south pole of the magnet for the outside of the magnet whereas the situation is reversed for inside of the magnet.