What is a reasonable value for estimating total equivalent length of the piping system, including fittings in a preliminary design? A) 200 to 250% of the linear pipe length as the total equivalent length of the piping system, including fittings. B) 150 to 200% of the linear pipe length as the total equivalent length of the piping system, including fittings. C) 250 to 300% of the linear pipe length as the total equivalent length of the piping system, including fittings. Which of the following fires would constitute a Class B fire? A) Involving combustible metals, such as magnesium. B) Involving wood, loth, paper, rubber, and many plastics. C) Involving flammable liquids, oils, greases, tars and flammable gases. D) Involving energized electrical equipment. 1) Ohm's Law states which of the following? A) Voltage is proportional to current and inversely proportional to resistance. B) Voltage is proportional to current and resistance. C) Voltage is inversely proportional to current and resistance.

A 2000/400 V, 100 kVA, 60 Hz step-down single-phase transformer has a primary and secondary resistances of 0.2ohm and 0.05 ohm respectively, the corresponding leakage reactances being 0.3 ohm and 0.01 ohm respectively.1. Calculate the equivalent resistance, reactance and impedance referred to the low-voltage (secondary) side.2. Find the high (primary) voltage when the transformer is supplying full-load current at rated secondary voltage at 0.8 powerfactor lagging.3. Draw the phasor diagram showing your answer in 2.

Explain the concept of distributed energy resources (DERs) and their impact on grid resilience.

1. Let a 5-kVA, 400/200 V transformer be approximately represented by a 2 Q reactance referred to a low voltage side. Considering the rated values as base quantities, (a) express the transformer reactance as a per-unit quantity. (b) express the reactance in per-unit quantity for the high voltage side. 2. The voltage v(t) = 141.4 cos (@t) is applied to a load consisting of a 10 W resistor in parallel with an inductive X1. = »L = 3.77 W. Calculate the real and reactive power absorbed by the load, and the power factor. 3. Table list a 4/0 copper conductor with 12 strands. Strand diameter is 0.3373 cm (0.1328 in. ). For this conductor (a) verify the total copper cross-sectional area of 107.2 mm² (211,600 c.mil) in the table. (b) verify the d.c. resistance at 50° C of 0.1876 W/ km or 0.302 W/ mi. Assume a 2% increase in resistance due to spiraling. (r@20°c = 1.77 x 10* W.m) (c) determine the percent increase in resistance at 60 hz versus d.c. (Reohz, so° c = 0. 1883 W / km) 4. a…