Professional Electrical Engineering Quiz 4 part 1

Heating effect of current has an undesirable side effect in

• electric oven

• immersion heater

• electric iron

• vacuum cleaner

Find the power factor of the impedance 5∠-25° Ω.

• 0.423 lagging

• 0.9063 leading

• 0.423 leading

• 0.9063 lagging

Convert the delta connected impedances of 12∠36° Ω to balanced wye connected impedances.

• 3∠36° Ω

• 6∠36° Ω

• 4∠36° Ω

• 12∠36° Ω

A series RLC circuit consists of a 5Ω resistor, a 0.2 H inductor, and a 50 µF capacitor. Compute the resonant frequency.

• 40 Hz

• 60 Hz

• 50 Hz

• 70 Hz

One KWHR is equal to ____ BTU.

• 360

• 3,413

• 3,600

• 1,000

Given a 100 kVA, 2400/240 V single-phase transformer. Find the current transformer (CT) ratio at the low voltage side.

• 700:5

• 600:5

• 500:5

• 400:5

Find the total resistance if 3 Ω is connected in series with the parallel combination of 4 Ω, 5 Ω, and 20 Ω.

• 4 Ω

• 5 Ω

• 6 Ω

• 7 Ω

Find the reactive factor of the load having 30 kW at 50 kVA.

• 0.6

• 0.5

• 0.8

• 0.7

A power plant has a peak demand of 80 MW and a connected load of 150 MW. It produces a total power of 400,000 MWHR annually. What is the annual load factor of the plant?

• 57.08%

• 30.44%

• 60.88%

• 45.66%

Find the emf induced on a 0.4 H inductor if the current changes from 10 A to 30 A in 0.2 second.

• 30 V

• 40 V

• 50 V

• 60 V