True False D.C shunt generators are most suitable for arc winding Answer by true or false * True False The purpose of armature winding is to carry armature current

In a DC generator, the effect of armature reaction on the main field is to * reverse it O distort it O reduce it O both (b) and (c)

A generator with simplex-lap winding has the following specifications: P = 4 poles turn coil s 1 (CONTINUATION AT commutator segments = 25 500 rpm speed conductor = 2 -> number of slots slot flux per pole = 1.8 x 106 Maxwell

An electromagnet has a movable iron part and dimensions of magnetic circuit with uniform cross section as shown in figure. The core is made of ferromagnetic material with relative permeability of 3000: a) b) c) Calculate the magnetic reluctance of the circuit and the inductance of the main winding. Determine the air-gap flux, the flux density and the field intensity of the core and gap. Because of a fault in the power supply, the exciting current is increased to 8 A causing the mobile element of the iron core to move to a zero gap position as a result of the excessive electromagnetic force action. If this movement occurs in 0.01 s, find the transient voltage induced in the test coil having two turns. 0.5 mm air-gap 2 cm 2 A 3 cm 2 cm 60 turns 18 cm test coil 24 cm 0.5 mm air-gap