The magnetic actuator shown in Fig. 1 is to be used to raise a mass m through a distance y. The coil has 5000 turns and can carry a current of 2A without overheating. The magnetic material can support a flux density of 1.5T with negligible field intensity. Fringing flux at the air gaps may be neglected.
a. Determine the maximum air gap y for which a flux density of 1.5T can be established with a current of 2.0A.
b. With the air gap determined in part (a), what is the force exerted by the actuator?
c. The mass density of the material is 7800 kg/m3. Determine the approximate value of the net mass m of the load which can be lifted against the force of gravity (at the sea level) by the actuator.
d. What current is required in the coil to lift the unloaded actuator?
e. What is the initial acceleration of the unloaded actuator if it is released when the coil current is 0.3A?

                                                                                                         Fig 1. Magnetic Actuator

Fixed part- Movable part- 8 cm 24 cm 4 cm 16 cm 4 cm