B.tech Examination papers dec 2014
sub - Switchgear and protection
Utu previous year question papers
uttarakhand technical university previous question papers
Time : 3 hrs
Q1: Attempt any four :
- Explain static relay and write its merits and demerits.
- Explain electromagnetic impedance relay.
- What are the various types of over current relays? Discuss their are of applications.
- Explain Directional Over-current relay?
- The current rating of a relay is 5A. PSM=2, TSM=0.3, CT ratio=400/5, fault current= 4000A. Determine the operating time of the relay. At TMS= 1, operating time various PSM are:
PSM= 2 4 5 8 10 20
operating time in seconds= 10 5 4 3 2.8 2.4
B.tech question papers
sub- Utilization of Electrical Energy and Traction.
UTU (uttrakhand technical university
previous year question papers)
Dec 2014
Q1: Attempt any four:
- What are the advantages of induction heating? Give classification of various heating methods.
- What is Ajax-Wyatt Furnace? Describe construction, principle of operation and application of this furnace.
- Discuss advantages of electrically produced heat. State the properties of a heating element used for this heating.
- Explain with help of neat sketch the working of Ajax Wyatt furnace.
- A 40KW 3 phase 400v, resistance oven is to employ nichrome strip 0.25mm thick for the three star-connected heating elements. If the wire temperature is to be 1200C and that of the charge is to be 800C, estimate a suitable width for the strip. Assume emissivity= 0.9 and radiating efficiency=0.5. Also determine the temperature of the wire when the charge is cold.
- What are the factors which limit the choice of frequency in induction and dielectric heating?
