INSIDE VIEW OF MOTOR

INSIDE VIEW OF TRANSFORMER

Why Generator & Alternator rated in kVA. Not in kW?

The power √3 VL IL Cos φ delivered by the alternator for the same value of current, depends upon p.f. (Power Factor=Cos φ) of the load. But the alternator conductors are calculated for a definite current and the insulation at magnetic system are designed for a definite voltage independent of p.f. (Cos φ) of the load. For this reason apparent power measured in kVA is regarded as the rated power of the alternator

MCQ ON CIRCUIT BREAKER

if we check dc circuit through a tester its glow. why ?

if indeed you do have one of the NEON type testers you will see two rods inside a glass bulb. With AC, both will tend to glow. Actually they are taking turns glowing at either 50 or 60 times per second, depending upon where in the world you live. For DC, only one electrode will glow. It will indicate the NEGATIVE lead. These units usually require somewhere around 55 to 60 volts to light up. Inside the housing, there is a resistor to limit the amount of current the bulb can draw.