Electrical Problems

Three coils are connected in delta to 3 phase, 3 wire 400 V, 50 Hz supply and takes a line current of 5A at 0.8 power factor lagging. Calculate the resistance and inductance of the coils Problem Question Three coils are connected in delta to 3 phase, 3 wire 400 V, 50 Hz supply and takes a line current of 5A at 0.8 power factor lagging. Calculate the resistance and inductance of the coils Topic AC Circuit Fundamentals Single phase…

Two watt-meters are used to measure power in a 3-phase balanced load. The watt-meter readings are 2 KW and 7.5 KW. Calculate (i) Total Power (ii) Power factor (iii) Total reactive power Problem Question Two watt-meters are used to measure power in a 3-phase balanced load. The watt-meter readings are 2 KW and 7.5 KW. Calculate (i) Total Power (ii) Power factor (iii) Total reactive power Topic AC Circuit Fundamentals Single phase AC Circuits Three phase AC circuits AC Circuit…

Three coils each of impedance 20∠60° Ω are connected in star to a 3 phase 400 V, 50 Hz supply. Find the reading on each of the two watt-meters connected to measure the power input. Problem Question Three coils each of impedance 20∠60° Ω are connected in star to a 3 phase 400 V, 50 Hz supply. Find the reading on each of the two watt-meters connected to measure the power input. Topic AC Circuit Fundamentals Single phase AC Circuits…

3 similar coils each having resistance of 10 ohms and reactance of 8 ohms are connected in star across 400 V, 3 phase supply. Determine (a) Line current (b) Total power (c) Reading of two watt-meters connected to measure power Problem Question 3 similar coils each having resistance of 10 ohms and reactance of 8 ohms are connected in star across 400 V, 3 phase supply. Determine (a) Line current (b) Total power (c) Reading of two watt-meters connected to…

A balanced 3 phase star connected system draws power from 440 V supply. The two watt-meters connected indicate W1 = 5KW and W2 = 1.2 KW. Calculate power, power factor and current in the circuit Problem Question A balanced 3 phase star connected system draws power from 440 V supply. The two watt-meters connected indicate W1 = 5KW and W2 = 1.2 KW. Calculate power, power factor and current in the circuit Topic AC Circuit Fundamentals Single phase AC Circuits…

A 3-phase load of 3 equal impedances are connected in delta across a balanced 400 V, 50 Hz, 3 phase supply which takes a line current of 10 A at a power factor of 0.7 lag. Calculate (i) Phase current (ii) Total Power in W (iii) Power in VA (iv) Power in VAR Problem Question A 3-phase load of 3 equal impedances are connected in delta across a balanced 400 V, 50 Hz, 3 phase supply which takes a line…

A Delta connected load consist of a resistance of 10 ohms and capacitance of 100 micro farad in each phase. A supply of 410 V at 50 Hz is applied to the load. Find line current, power consumed by the load and power factor Problem Question A Delta connected load consist of a resistance of 10 ohms and capacitance of 100 micro farad in each phase. A supply of 410 V at 50 Hz is applied to the load. Find…

A coil of resistance 10 ohms and inductance of 0.1 H is connected in series with a 150 micro farad capacitor across a 200 V, 50 Hz supply. Calculate (i) Inductive reactance (ii) Capacitive reactance (iii) Impedance (iv) Current (v) Power factor (vi) Voltage across coil (vii) Voltage across capacitor. Problem Question A coil of resistance 10 ohms and inductance of 0.1 H is connected in series with a 150 micro farad capacitor across a 200 V, 50 Hz supply.…

An inductive coil takes a current of 33.24 A from 230 V, 50 Hz supply, if the resistance of coil is 6 ohms. Calculate inductance of the coil and power taken by the coil. Problem Question An inductive coil takes a current of 33.24 A from 230 V, 50 Hz supply, if the resistance of coil is 6 ohms. Calculate inductance of the coil and power taken by the coil. Topic AC Circuit Fundamentals Single phase AC Circuits Three phase…

An alternating voltage of (160+j 120) V is applied to a circuit and the current is given by (6-j8) A. Find the values of circuit elements by assuming f=50 Hz. Calculate the power factor of the circuit and power consumed by the circuit. Problem Question An alternating voltage of (160+j 120) V is applied to a circuit and the current is given by (6-j8) A. Find the values of circuit elements by assuming f=50 Hz. Calculate the power factor of…

A resistance of 7 ohms is connected in series with a pure inductance of 31.8 mH and the circuit is connected to a 100V, 50 Hz sinusoidal supply. Calculate (i) Circuit current (ii) Phase angle (iii) Power factor (iv) Power Problem Question A resistance of 7 ohms is connected in series with a pure inductance of 31.8 mH and the circuit is connected to a 100V, 50 Hz sinusoidal supply. Calculate (i) Circuit current (ii) Phase angle (iii) Power factor…

A coil of resistance 20 ohms and inductance of 0.0382 henry is connected in parallel to a circuit consisting of a 150 micro farad in series with a 10 ohms resistor. The arrangement is connected to a 230 V, 50 Hz supply. Determine current in each branch. Also find total supply current. Problem Question A coil of resistance 20 ohms and inductance of 0.0382 henry is connected in parallel to a circuit consisting of a 150 micro farad in series…

A series RLC circuit with 100 ohms, 25 micro farad and 0.15 henry is connected across 220 V, 50 Hz supply. Calculate (i) Impedance (ii) Current (iii) Power consumed (iv) Power factor of the circuit Problem Question A series RLC circuit with 100 ohms, 25 micro farad and 0.15 henry is connected across 220 V, 50 Hz supply. Calculate (i) Impedance (ii) Current (iii) Power consumed (iv) Power factor of the circuit Topic AC Circuit Fundamentals Single phase AC Circuits…

A series RLC circuit is composed of a 100 ohms resistance, 1 H inductance and 5 micro farads capacitance. A voltage of v(t)=141.4 cos 377t volts is applied to the circuit, determine the current and voltages across resistance, inductance and capacitance. Problem Question A series RLC circuit is composed of a 100 ohms resistance, 1 H inductance and 5 micro farads capacitance. A voltage of v(t)=141.4 cos 377t volts is applied to the circuit, determine the current and voltages across…

For the current waveform shown in figure, find (i) Peak current (ii) Average current (iii) Periodic time (iv) Frequency (v) Instantaneous current at t=3 ms. Problem Question For the current waveform shown in figure, find (i) Peak current (ii) Average current (iii) Periodic time (iv) Frequency (v) Instantaneous current at t=3 ms. Topic AC Circuit Fundamentals Single phase AC Circuits Three phase AC circuits AC Circuit Problems Two alternating currents in a parallel circuit are represented by i_1=5 sin(omega)t and…

A parallel circuit consists of 20 ohms in series with an inductive reactance of 15 ohms in one branch and resistance of 30 ohms in series with a capacitive reactance of 20 ohms in the other branch. Determine the current and power dissipated in each branch if the total current drawn is 10 at an angle of (-30) degrees. Problem Question A parallel circuit consists of 20 ohms in series with an inductive reactance of 15 ohms in one branch…

An alternating current i is given by i=100 sin 314 t. Find the (i) Amplitude (ii) Frequency (iii) Time period (iv) Form factor (v) Peak factor Problem Question An alternating current i is given by i=100 sin 314 t. Find the (i) Amplitude (ii) Frequency (iii) Time period (iv) Form factor (v) Peak factor Topic AC Circuit Fundamentals Single phase AC Circuits Three phase AC circuits AC Circuit Problems Two alternating currents in a parallel circuit are represented by i_1=5…

The instantaneous values of two alternating voltages are represented respectively by v_1= 60 sin theta volts and v_2=40 sin((theta-pi/3) volts. Calculate the (i) Sum & (ii) Difference of voltages. Problem Question The instantaneous values of two alternating voltages are represented respectively by v_1= 60 sin theta volts and v_2=40 sin((theta-pi/3) volts. Calculate the (i) Sum & (ii) Difference of voltages. Topic AC Circuit Fundamentals Single phase AC Circuits Three phase AC circuits AC Circuit Problems Two alternating currents in a…

Given v=200 sin 377t volts and i=8 sin(377t -30 degree) amperes for an AC circuit, determine (i) Power factor (ii) Power (iii) Apparent power (iv) Reactive power. Indicate the unit of power calculated. Problem Question Given v=200 sin 377t volts and i=8 sin(377t -30 degree) amperes for an AC circuit, determine (i) Power factor (ii) Power (iii) Apparent power (iv) Reactive power. Indicate the unit of power calculated. Topic AC Circuit Fundamentals Single phase AC Circuits Three phase AC circuits…

The equation for an AC voltage is given as v=0.04sin(2000t+60 degree)V. Determine the frequency, the angular frequency, instantaneous voltage when t=160 micro sec. What is the time represented by a 60 degree phase angle. Problem Question The equation for an AC voltage is given as v=0.04sin(2000t+60 deg)V. Determine the frequency, the angular frequency, instantaneous voltage when t=160 micro sec. What is the time represented by a 60 degree phase angle. Topic AC Circuit Fundamentals Single phase AC Circuits Three phase…