PART B

೩ 4. Show that the rotational mutual inductance or motional inductance ofa DC machine as:
221
‏خاو‎ == (3)
TIA Ids

b. Obtain the voltage and torque equation of a separately excited DC motor from
its generalized mathematical model. (4) c. Derive the transfer function of

separately excited DC generator under no load operation. (2)

a. A separately excited DC generator gave a no load output voltage of 240V ata
speed of (Dr and a field current of 3A. Find the generated emf per field ampere,
Md(Dr. Also find the voltage V2 as a function of time, when a 240V is suddenly
applied to the field winding with the armature running at constant speed (Dr.
The other constants of the generator are rf= 60Q, LF60H, ra=0.02Q, La=0.01H
and Rc=0.38Q. (9)

a. Derive the power expression for salient pole synchronous machine in terms of
load angle and draw the power angle characteristics. (6) b. Derive the voltage
equations in matrix form for a three phase synchronous

machine with no amortisseurs. (3)
PART C

a. Derive the equivalent circuit of a double cage induction motor with the help
of its generalized mathematical model. (9)

b. Draw the torque slip characteristics of poly phase Induction motor. (3)

a. Draw the primitive machine diagram of double cage poly phase induction motor and obtain the voltage

equation in matrix form. (8)

b. Derive the equivalent circuit of a double cage poly phase induction motor with

the help of its generalized mathematical model. (4)

a. Write down the electeomagnetic torque equations from the primitive
machine model of a single phase induction motor and obtain the equivalent
circuit for a single phase induction motor.(9)

b. Explain briefly the double field revolving theory of single phase Induction
motor. (3)