Important Science Fact For Railway Exam
1-Tritium is radioactive isotopes of Hydrogen.
2-Tuning of radio is an example of resonance.
3-Cobalt-60 is used in Leukemia treatment
4-Cybernetics is study of communication between human and machine.
5-The filament of Halogen lamp is made of tungsten-iodine mixture.
6-Ceramic is used in Super-conductivity.
7-A transformer which increases the applied e.m.f. of an alternating current is called Step-up transformer.
8-Transformer, which decreases applied e.m.f. of alternating current is called step-down transformer.
9-A device which convert mechanical energy into electric energy is called dynamo. However, if it produces a fairly large amount of power, it is called Generator.
10-Generator is based on the principle of electromagnetic induction.
in generator, armature consists of laminated soft iron core, from the centre of which passes a steel axle.
11-Slip sings of generator are made of gun metal.
12-Brushes of generator are made out of carbon or gun metal.
13-Coulumb is the unit of electric charge (coulumb = ampere/second).
14-1 coulumb = 6.25
15-Magnetic effect of electric current was discovered by Weston.
16-Ammeter is used in DC as well as in AC.
17-Resistance of Ammeter is very low.
18-Resistance of Voltmeter is very high.
19-Volmeter measures potential difference between two points.
20-A parallel combination of a galvanometer and a small resistance is equivalent to an ammeter.
21-A series combination of a galvanometer and a high resistance is equivalent to a voltmeter.
22-Ammeter is always connected in series while voltmeter is always connected in parallel.
23-Electron volt is the unit of energy.
24-Watt is the unit of electric power, watt = volt x ampere =Kilowatt hour (KWH) is also the unit of electric power 1 KWH = 3.6 x J
25-The resistance of low power (watt) bulb is high
