Example with 778 wave-connected armature conductors and run- ning at 500 rp.m. supplies a lood of 12.5 2 resistance at terminal voltage of 50 V The arımature resistance is 0.24 2 and the field resistance is 250 2 Find the armature current, the induced e.m.f. and the flux per pole. An 8-pole d.c. shunt generator

Write the types and shortly explain the magnetic losses for electrical machines

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

(9) The hysteresis losses in electrical machines reduced. a- By core lamination. b- By core isolation. c- By choosing another type of iron. (10) The eddy current losses in electrical machines reduced. d- By core lamination. e- By core isolation. f- By choosing another type of iron.

(5) The saturation in transformer appears: a- At no-load. b- At half-load. c- At full-load. (6) The only parts suffers from eddy currents in DC motors: a- The stator. b- The rotor. c- The stator and rotor.

Q3) The armature of a 4-pole DC machine has 240 coils wound in lap formation. Each coil generates a voltage of 4 V and carries a current of 5 A. a) Calculate the total generated voltage in the armature,Eg. b) Find the current in each parallel path and total armature current. c) If the armature is rewound in wave formation, find the generated voltage, Eg, current per path and total armature current. Assume number of coils are fixed at 240.

Answer in short please i will like....

(a) Using Faraday's Law as a starting point prove that the maximum operating voltage of a transformer to avoid magnetic saturation is given by the following equation: Q3 Vrms=4.44N.f.Bmax.Ac where: Vrms = maximum rms operating voltage avoiding magnetic saturation N = number of turns in the winding f= electrical frequency (Hz) Bmax = maximum flux density (T) (typically 1.3T for iron) Ac = Iron core cross sectional area (m²) A single phase transformer has the parameters shown on Table Q3 and is connected to a 230 V and 50 Hz AC supply. Sketch the equivalent circuit and using this determine: (b) (i) The Secondary voltage under Open Circuit (Vsoc) (ii) The Secondary voltage, current and power (W) given a 0.6 Q resistive Load. (iii) The efficiency and voltage regulation at this load Through suitable calculations determine whether the size, weight or cost of this transformer could be reduced such that it operated below a maximum flux density of 1.3 T and the current density in both windings…

please include circuit design

Q3) The armature of a 4-pole DC machine has 240 coils wound in lap formation. Each coil generates a voltage of 4 V and carries a current of S A. a) Calculate the total generated voltage in the armature,Eg. b) Find the current in each parallel path and total armature current. c) If the armature is rewound in wave formation, find the generated voltage, Eg. current per path and total armature current. Assume number of coils are fixed at 240.