K.C.S.E Physics Q & A - MODEL 2016PP2QN14

K.C.S.E Physics Q & A - MODEL 2016PP2QN14

​Figure 6 shows a simple electric bell circuit

​(i)Name the parts labeled
(I) D
(II) E
(ii)When the switch is closed, the hammer hits the gong repeatedly.
Explain why:
(I) the hammer hits the gong. 
(II) the hammer hits the gong repeatedly.
(b) An electric bulb is rated 60 W, 240 V. Determine:
(i) the current that flows through it when it is connected to a 240 V supply.
(ii) the resistance of the bulb.

answers

​(i)D-Soft iron armature
 E-Contact screw
(ii) (I)Soft iron core is magnetized
    It attracts the armature
(II) Contact is broken
 The core then loses magnetism
 Armature spring back making contact again