[b][/b]: When the key is closed, current flows in the circuit thereby magnetising the electromagnet. The soft iron armature is thus attached to the electromagnet, causing the hammer to strike the gong.
When the armature is attracted, a gap is created at the contact and the circuit breaks. The electromagnet loses its magnetism and the armature falls back to its original position by the pull of this spring. This process of make and break is repeated thereby making the bell to ring continuously
(i) E = IR - 0.2(2 + R) R = Ressistence of bell 3 = 0.2(2 + R)
15 = 2 + R
R\(_\theta\) = 15 - 2 = 13e
(ii) E = 1(0.5 _ R) 1.5 = I(0.5 _ 13) = I(13.5)
I = \(\frac{15}{135}\) = 0.11A