Question
Question: A conducting loop is held above a current carrying wire \[PQ\] as shown below. Depict the direction ...
A conducting loop is held above a current carrying wire PQ as shown below. Depict the direction of current induced in the loop when the current in the wire PQ is constantly increasing.
Solution
We know that a current carrying conductor can produce magnetic fields around itself. And we also know that current can be produced by a varying magnetic field. The current produced is called induced current and its direction is given by right hand thumb rule.
Complete step by step answer:
We know that a current carrying conductor, here wire PQ produces a magnetic field around the wire. Then the direction of the magnetic field is given by the write hand thumb rule. According to this, if the right thumb points towards the direction of the current, then the direction of the magnetic field is given by the curled fingers.
Here, consider a point A inside the circle as shown in the figure below. Then using the right hand thumb rule, we see that the magnetic field lines are pointed inside the paper and denoted by ⊗
Since the current in the wire PQ is increasing, this produces a magnetic flux at A.
We also know that a varying magnetic flux can induce current. Thus the circular coil carries induced current due to the magnetic flux. The direction of this current is again given by the right hand thumb rule. Here, point the thumb in the direction of the magnetic field, then the direction of the current is given by the curled fingers. Then the direction of the current is clockwise or as given in the figure below.
Note: That direction of current and the direction of magnetic field are interrelated; when one is given the other can be found using the right hand thumb rule. Also note that the current carrying conductor produces magnetic field and change in magnetic flux produces current.