moving coil and moving iron meters

Its how they are constructed//..

A moving iron meter will respond to both ac and dc voltages/currents through it.

A moving coil only responds to dc voltages/currents through it...

A moving coil can be made to respond to ac by recitfying the ac first...

I think you are getting a little mixed up perhaps?

John.

Have a look at these descriptions from All About Circuits. Explains it well.

a moving coil responds to AC and DC. With DC it moves against the coiled spring until the spring balances the torque from the current.

With AC it moves a very little bit in one direction and when the current reverses it goes the other way. So it stays on zero and gets a little blurred. Quite visible on the old 25 hertz systems, but much less on 50/60 Hz. Lighter needles are more compliant and move more.

can u explain the working of moving iron type meters?

The 3rd figure in the link I gave in the post above shows a form of moving iron meter. Here it is again, for your convenience:

As you will see, there is a fixed coil through which the current to be measured flows, and an iron vane attached to the pointer. The iron doesn't care what type of magnetic field is attracting it - AC or DC - but the higher the current, the greater the attractive force, so the greater the deflection of the pointer. There is a spring (not shown) which keeps the pointer at 0 when no current flows.