1. Describe the working of a sodium vapour lamp. Also explain the relevant features.
2. Discuss the common troubles that occur in a fluorescent lamp and remedies that are to be taken.
3. Explain various methods of electric braking.
4. (a) Discuss the method of plugging as applied to dc shunt motor
(b) Explain the rheostatic braking as applied to dc series motor.
5. Sketch the typical speed-time curve for (I) main line service (II) suburban service (III) urban service.
6. Derive an expression for specific energy output on a level track using a simplified speed-time curve.
7. What are the various factors affecting the specific energy consumption?
8. A train consists of 12 coaches each weighting 30 tonne is to be haulted by a electric locomotive on main line with an acceleration of 0.8 km ph PS up a gradient of 1 %. The rotational inertia is to be 4 % for coaches and 15% for locomotive. The maximum co-efficient of adhesion is 0.2 and the tractive resistance 49 N/tonne. Determine the adhesive weight and the number of driving axles.
9. Compare the following systems of track electrification as regards to operating voltages, economy in operating and suitability.
i) Single phase ac systems.
ii) Composite system.
10. Compare dc and ac system of traction from the point of Main Line railway service.
11. Discuss why a dc series motor is ideally suited for traction service?
12. Explain the working of a filament lamp with a neat sketch.