An electric heater is rated 2200 VA, 220V. If the heater is operated for 1 hour, calculate the energy consumed:
(i) in kWh
(ii) in J
A pair of scissors is used to cut a piece of a cloth by keeping it at a distance of 8.0 cm from its rivet and applying an effort of 10 kgf by fingers at a distance of 2.0 cm from the rivet.
(a) Find : (i) the mechanical advantage of scissors, and (ii) the load offered by the cloth.
(b) How does the pair of scissors act : as a force multiplier or as a speed multiplier ?
Complete the following sentences :
(a) Mechanical advantage = ............ × velocity ratio
(b) In class II leer, effort arm is ........ than the load arm.
(c) A scissors is a ........ multiplier
Complete the following sentences:
(a) 1 J =....... calorie.
(b) 1 kWh= ........J.
A machine works as a (i) force multiplier, (ii) speed multiplier. In each case state whether the velocity ratio than or less than 1.