Electrical Engineering Materials Question Paper of 3rd Semester Electrical(D) Download Previous Years Question Paper 12

S.B. Roll No.______

ELECTRICAL ENGINEERING MATERIALS

3^rd Exam/Elect/0152/May 10

Duration: 3 hrs.

1.     Fill in the blanks

a.     In conductors the temperature coefficient of resistance is _________

b.     The commercial unit of electrical energy is _______

c.      KOH electrolyte is used in _______

d.     Hennery is unit of _______

e.      In a pure ___________  circuit current leads voltage by 90̊

f.       ____________ is defined as the cosine of angle between voltage and current.

g.     ____________ power is measured in Var.

h.     The base of an _______ triangle represents resistance.

i.       In _________ type of connection I_L =I_pn

j.       Acceding to KCL, algebraic sum of all the currents meeting at a point is ________

Section –B

Note: Attempt any five questions

2.      

a.     State and explain Kirchhoff’s current law.

b.     With neat sketch explain the construction of silver oxide cell.

c.      Derive an expression for total inductance if two coils are joined in parallel considering both the cases of additive and subtractive fluxes.

d.     Differentiate between AC and DC in tabular form.

e.      Derive an expression for average value of current.

f.       Define power factor. What are the disadvantages of low power factor.

g.     What are the advantages of three phase system over single phase system.

h.     Define self inductance (L) and prove that L = N0/1

Section –C

3.     State and prove The venin’s theorem.

4.     Derive an expression  for energy stored n an inductor.

5.     What neat sketches explain the two different methods of charging of lead acid battery.

6.     Derive an expression for current, voltage and power consumed in a pure inductive circuit. Also draw and explain power curve.

7.     Three inductive coils of 0.05 H are connected in star to a 3 phase 200 volts,  50 Hz system. Calculate the inductance of 3 coils which when connected in delta to the same system, will take same line current.