Note for Basic Electrical Engineering - BEE By Dr. RAMAPRASAD PANDA

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EEE Department Silicon Institute of Technology Bhubaneswar Tutorial: 1 (Fundamentals of Electric Circuits) Q.1 The battery in the accompanying circuit supplies power to the resistors R1, R2, and R3. Use KCL to determine the current iB, and find the power supplied by the battery if Vbattery = 3 V. Q.2 Determine the current through R3 in Figure for: VS = 12V RS = 1 kΩ R1 = 2 kΩ R2 = 4 kΩR3 = 6 kΩ Q.3 If an electric heater requires 23 A at 110 V, determine: a. The power is dissipates as heat or other losses. b. The energy dissipated by the heater in a 24-hour period. c. The cost of the energy if the power company charges at the rate 6 cents/kW-h. Q.4 In the circuit shown in Figure, determine the terminal voltage of the source, the power supplied to the circuit (or load), and the efficiency of the circuit. Assume that the only loss is due to the internal resistance of the source. Efficiency is defined as the ratio of load power to source power. VS = 12 V RS = 5 kΩ RL = 7 kΩ Q.5 For the circuit shown in Figure, a. Determine which components are absorbing powers and which are delivering power. b. Is conservation of power satisfied? Explain your answer. Basic Electrical Engineering

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EEE Department Silicon Institute of Technology Bhubaneswar Q.6 Use Kirchhoff’s current law to determine the current in each of the 30" resistors in the circuit of Figure Q.7 An electric heating pad rated at 110 V and 55 W is to be used at a 220-V source. It is proposed to connect the heating pad in series with a series-parallel combination of light bulbs, each rated at 110 V; bulbs are available having ratings of 25 W, 60 W , 75 W, and 100 W. Obtain a possible scheme of the pad-bulbs combination. At what rate will heat be produced by the pad with this modification? [One 100-W bulb in series with a parallel combination of two 60-W bulbs, 54.54 W.] Q.8 Find the voltage of point A with respect to point B in the Fig shown. Is it positive with respect to B ? Q.9 Determine the current by the source in the circuit shown below. Q.10An electric lamp whose resistance, when in use, is 2 n is connected to the terminals of a dry cell whose e.m.f. is 1.5 V. If the current through the lamp is 0.5 A, calculate the internal resistance of the cell and the potential difference between the terminals of the lamp. If two such cells are connected in parallel, find the resistance which must be connected in series with the arrangement to keep the current the same as before. [1 Ω ; 1 V ; 0.5 Ω] Basic Electrical Engineering