What happens when iron rod is inserted in coil?

As the iron rod is inserted, the magnetic field inside the coil magnetizes the iron increasing the magnetic field inside it. Hence, the inductance of the coil increases. Consequently, the inductive reactance of the coil increases.

What happens to the brightness of the lamp if a soft iron rod is introduced into the coil?

as iron is inserted, the magnetic field inside of the coil increases. hence, the inductive reactance increases. from these relation I is inversely proportional to L. therefore, current decreases as increase in L and hence brightness of bulb decreases.

Why does deflection increase when iron rod is inserted?

This happens because iron is a ferromagnetic substance and it lets more number of magnetic lines of force to pass through it. Since, flux increases the induced emf also increases, hence, the deflection of the galvanometer also increases.

How does iron core affect inductance?

A coil wound on a soft iron core far more effectively chokes the increase of a current than the same coil with an air core. The iron core increases the inductance; for the same rate of change of the current in the coil, a greater opposing electromotive force (back emf) is present to choke the current.

Why do iron rods move apart when the switch is closed?

(a) When the switch is closed, the two rods move apart. (i) Explain why this happens. The rods are both magnetised in the same direction so that the N or S poles are next to each other’. The rods repel each other and roll apart.

What happens if iron rod is inserted in inductor connected to lamp and AC source in series?

If an iron rod is inserted in the inductor, then the value of inductance L increases. As such, the current through the bulb will decrease, thus, decreasing the brightness of the bulb.

Why an iron core increases inductance?

Iron core has high magnetic permeability. A material with high magnetic permeability will have high magnetic flux for a given magnetic field force. Greater the permeability of the material used greater is the inductance.

What happens when you put a nonferrous rod in a coil?

This current causes a reverse magnetic field that repels the applied changing magnetic field. This is why a nonferrous metal rod inserted in a coil reduces the inductance. It also increases power loss as heat in the rod. But this happens in ferrous metals, too.

What happens to the ring when the coil is closed?

A metal ring slides over the rod and rests on the wire coil. Initially the switch connecting the coil to a battery is open, but when it is closed, the ring flies into the air. Explain why this happens. When the switch is closed, a magnetic field is produced in the wire coil and in the iron rod.

How does a magnetic field affect the inductance of a coil?

There is a secondary effect – a changing magnetic field induces a current in conductive materials. This current causes a reverse magnetic field that repels the applied changing magnetic field. This is why a nonferrous metal rod inserted in a coil reduces the inductance. It also increases power loss as heat in the rod.

What is the direction of current induced by a magnetic rod?

The direction of the current induced by the rod’s downward motion is counterclockwise, since this direction produces a magnetic field within the loop that points out of the page—in the same direction as the original field.