NCERT Solutions for Class 10 Science Chapter 13
1: Why is the Oersted Experiment known as the base of electromagnetic effect?
Hans Oersted, in 1820, by his experiment observed that when an electric current is passed through a conducting wire, a magnetic field is produced around it. The presence of a magnetic field at a point around a current-carrying wire can be detected with the help of a compass needle. If a compass needle is brought in the vicinity of the current-carrying wire then it is observed that the needle of the compass deflects in a definite direction. The direction of deflection of the needle is reversed if the direction of current is reversed.
2: What is the rule to find the direction of the magnetic field?
Experimentally the direction of the magnetic field at a point is determined with the help of a compass needle. But theoretically, the direction of the magnetic field (or magnetic field lines) produced due to the flow of current in a conductor can be determined by various rules. One such rule is the right-hand sum rule which states that if we hold the current-carrying conductor in the right hand such that the thumb points in the direction of the flow of current and the fingers encircling the wire points the direction of the magnetic field lines.
3: Vedantu explains the pattern of the magnetic field lines in brief.
From the pattern of the magnetic field lines its is to be noted that:
In the vicinity of wire at P and Q, the magnetic field lines are nearly circular.
Within the space enclosed by the wire, the magnetic field lines are in the same direction.
Near the centre of the loop, the magnetic field lines are nearly parallel and the magnetic field may be assumed to be nearly uniform in a small space near the centre.
At the centre, the magnetic field lines become denser (i.e., the magnetic field strength is increased) if
the strength of the current in the loop is increased and
the number of turns in the loop are increased.
Since the magnetic field lines pass through the loop in the same direction, we can assume that one face of the loop acts as a North pole and the other acts as a south pole. Thus, the loop acts as a dipole.