4) In an automatic electric iron, a thermostat is used to :

reduce the current for controlling the temperature

change the direction of current flow for controlling the temperature

regulate the heat and thus the temperature by switching the element to ON-OFF

switch ON-OFF the indicator lamp

Answer is:

regulate the heat and thus the temperature by switching the element to ON-OFF

repulsion motor

permanent capacitor motor

capacitor-start induction-motor

shaded-pole motor

Answer is:

decrease the current

drop the voltage applied to the fan

increase the speed

increase the torque

Answer is:

increase the speed

protect the fan in case a fault occurs

produce a phase-shift

control the speed

Answer is:

it has no element

its element is closed in a sand filled spiral, narrow pipe

it can't be opened

it gets burst on becoming defective

Answer is: