special test questions for II yr and III yr

special test questions for II yr

Sub- NT:

Short answer questions: (2*4=8 marks)

1. Give the table for two port network variable equations, dependent & independent variables,
symmetry and reciprocity condition.
2. Give the table for two port network variable conversion variables.

Long answer questions(2*6=12 marks)

1. Find the h-parameters for the fallowing networks

2.Find the y-parameters for the fallowing networks

special test questions for III yr

Sub- EMT:

1.  Derive phase angle error and Ratio error of current transformer.

2. Derive phase angle error and Ratio error of potential transformer.

3. Discuss about Weston Frequency meter with a neat diagram.

4. A power primary C.T has 300 secondary turns. The total resistance and reactance for the secondary circuit are 1.5 ohms and 1 ohm respectively. When 5A flows through the secondary winding, the magnetizing m.m.f is 100 AT and the iron loss component is 40 A. Determine the ratio and phase angle errors of the C.T at this load.

5. A potential transformer has a primary resistance of 300 ohms, a primary reactance of 600 ohms, a secondary resistance of 0.75 ohms and a secondary reactance of 1.5 ohms. The primary to secondary turns ratio is 20:1, the primary voltage is 2000V. Neglect the magnetizing and core loss current. Determine the voltage ratio correction factor, ratio error and the phase angle error when the burden on the secondary of the transformer is

            a) 50VA at 0.6 p.f lagging

            b) 25VA at 0.6 p.f leading