Ee 2024 preboard

The power generated by some steam power plants drops in the summer because _______

I. The water in the lake decreases

II. The lake temperature increases

III. Many people go swimming in the lake

• I only

• II only

• III only

• none of these

A three phase, wye connected, 20 - MW load of power factor 0.866 lagging is to be supplied by a transmission line at 138 kV. It si desired that the line losses not exceed 5 percent of the load. If the per-phase resistance of the line is 0.7 ohms, what is the maximum length of the line?

• 51 km

• 42 km

• 63 km

• 56 km

A 15 - ohm resistor is connected in parallel with a series combination of resistors of 8 and 12 ohms. If the voltage drop across the 8-ohm resistor is 48 V, what is the total current in A?

• 16

• 18

• 22

• 20

Which of the following plants will take least time in starting from cold cinditions to full load operations?

• gas turbine power plant

• steam turbine power plant

• nuclear power plant

• hydroelectric power plant

An induction motor draws 50 KW at a 0.60 lagging power factor from a 480 V, 60 Hz source. What parallel capacitor will increase the overall power factor to 0.90 lagging?

• 532 μF

• 489 μF

• 704 μF

• 582 μF

When one coil of a magnetically coupled pair has a current of 7.0 A, the resulting fluxes Φ11 and Φ12 are 0.50 mWb and 0.75 mWb, respectively. What is the coefficient of coupling k, if the number of turns N1 and N2 are 100 and 300, respectively?

• 0.4

• 0.8

• 0.2

• 0.6

Regarding Thevenin's equivalent, which of the following is NOT correct?

• The voltage source in the thevenin equivalent circuit is the open circuit voltage of the network when load is disconnected.

• The Thevenin equivalent resistance

  ( impedance ) is the resistance

  ( impedance ) of the network when all voltage sources are short circuited.

• Thevenin equivalent resistance is calculated when all voltage sources are open circuited.

• Thevenin equivalent is the voltage equivalent of the network.

Which of the following is NOT a type of distance relay?

• mho relay

• reactance relay

• overcurrent relay

• impedance relay

What is the total resistance of eleven 33 kΩ resistors connected in parallel?

• 33 kΩ

• 3 kΩ

• 363 kΩ

• 11 kΩ

A 69 kV three - phase transposed line is composed of one ACSR 336,400 cmil, 26/7 Linnet conductor per phase with a horizontal configuration of D12 = 5 ft, D23 = 5 ft and D13 = 10 ft. The conductors have a diameter of 0.721 inch and a GMR of 0.0243 ft. Find the inductance per phase per kilometer of the line.

• 1.0963 mH/km

• 1.1116 mH/km

• 1.1505 mH/km

• 1.1233 mH/km