Question

can we use a u shaped permanent magnet in making an electric bell

Answer 1

Yes you can use u shaped permanent magnet in making an electrical bell.
there is no problem as you are using magnet it will work.

Answer 2

Using a permanent magnet in an electric bell........... will not work...... B'CUZ if you do this.....the armature will always be attracted towards magnet.... Nd'there would be no sudden strike due to which sound is produced.....