Electrical Engineering · Question Bank

Fundamentals of Electricity

5 of 141 questions match. Answer in your head first, then check the solution.

#1📜 EE Pre-Board March 2013📘 PowerhouseMedium

A total of 0.8 kg of water at 20 °C is placed in a 1-kW electric kettle. How long a time in minutes is needed to raise the temperature of the water to 100 °C?

A4.46 min

B4.56 min

C5.32 min

D6.34 min

#2📜 EE Pre-Board March 2014📘 PowerhouseMedium

An aluminum cable has 10 identical strands, a length of 1,500 m and a diameter of 2.50 mm each. What is the resistance of the cable?

A5.63 Ω

B0.563 Ω

C8.63 Ω

D0.863 Ω

#3📜 EE Pre-Board March 2014📘 PowerhouseMedium

A light bulb having a tungsten filament draws 0.5 A at 110 V. The cold resistance of the filament is 20 Ω at 20 °C. At this temperature the temperature coefficient of resistance for tungsten is 0.005 per °C. Determine the operating temperature of the bulb.

A1,980 °C

B2,080 °C

C2,120 °C

D2,020 °C

#4📜 EE Pre-Board August 2014📘 PowerhouseMedium

An electric heater develops a power of 1 kW when run on a 230 V supply. If the heater resistance wire has a diameter of 0.5 mm and a resistivity of \(60 \times 10^{-8}\) Ω-m, find the minimum length of the wire required.

A11.33 m

B13.3 m

C15.3 m

D17.3 m

#5📜 EE Pre-Board August 2017📘 PowerhouseMedium

A transmission line cable consists of 26 strands of identical copper conductor, each 1.255 mm in diameter. The length of the cable is 10 km, but because of the twist of the strands, the actual length of each conductor is increased by 5%. If the resistivity of copper is \(1.72 \times 10^{-8}\) Ω·m, what is the resistance of the cable in ohms?

A5.35

B146

C0.562

D5.62

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