The three non -inductive loads of 5 kW, 3 kW and 2 kW are connected in a star network between R, Y and B phases and neutral. The line voltage is 400 V. The current in the neutral wire is nearly (a) 11 A (b) 14 A (c) 17 A (d) 21 A

1 Answer

Answer :

The three non -inductive loads of 5 kW, 3 kW and 2 kW are connected in a star network between R, Y and B phases and neutral. The line voltage is 400 V. The current in the neutral wire is nearly 11 A

Related questions

Description : 4. A three-phase, four-wire system having \( 250 V \) line-to-neutral has the following loads connected between the respective lines and the neutral. Calculate the current in the neutral wire?\[Z_{R}=20 \angle 0^{\circ} ... Z_{Y}=20 \angle 35^{\circ} \Omega, Z_{B}=20 \angle-55^{\circ} \Omega\](10M)

Last Answer : 4. A three-phase, four-wire system having \( 250 V \) line-to-neutral has the following loads connected ... =20 \angle-55^{\circ} \Omega \] (10M)

Description : 4. A three-phase, four-wire system having \( 250 V \) line-to-neutral has the following loads connected between the respective lines and the neutral. Calculate the current in the neutral wire?\[Z_{R}=20 \angle 0^{\circ} ... Z_{Y}=20 \angle 35^{\circ} \Omega, Z_{B}=20 \angle-55^{\circ} \Omega\](10M)

Last Answer : 4. A three-phase, four-wire system having \( 250 V \) line-to-neutral has the following loads connected ... =20 \angle-55^{\circ} \Omega \] (10M)

Description : 4. A three-phase, four-wire system having \( 250 V \) line-to-neutral has the following loads connected between the respective lines and the neutral. Calculate the current in the neutral wire?\[Z_{R}=20 \angle 0^{\circ} ... Z_{Y}=20 \angle 35^{\circ} \Omega, Z_{B}=20 \angle-55^{\circ} \Omega\](10M)

Last Answer : 4. A three-phase, four-wire system having \( 250 V \) line-to-neutral has the following loads connected ... =20 \angle-55^{\circ} \Omega \] (10M)

Description : The locked rotor current in a 3-phase, star connected 15 , kW 4 , pole 230 V , 50 Hz induction motor at rated conditions is 50 A. Neglecting losses and magnetizing current, the approximate locked rotor line current drawn when the motor ... Hz supply is  (A) 58.5 A (B) 45.0 A (C) 42.7 A (D) 55.6 A

Last Answer : The locked rotor current in a 3-phase, star connected 15 , kW 4 , pole 230 V , 50 Hz induction motor at rated conditions is 50 A. Neglecting losses and magnetizing current, the approximate locked rotor line current drawn when the motor is connected to a 236 , V 57 Hz supply is 45.0 A 

Description : Which of the following statements are true? i) reactive current is necessary to build up the flux for the magnetic field of inductive devices ii) some portion of reactive current is converted into work iii) the cosine of angle ... called power factor a) i & iv b) ii & iii c) i & iii d) iii & iv

Last Answer : a) i & iv

Description : Capacitors can be used in electric distribution systems to improve power factor. This is accomplished by seesawing energy between the capacitor and the _____________. A. generator B. inductive loads C. resistive loads D. all of the above

Last Answer : Answer: B

Last Answer : If R, L and C are the parameters of a resistor then the condition for the resistor to be non-inductive is L = CR2 .

Description : A 400 V, 15 kW, 4-pole, 50 Hz, Y-connected induction motor has full load slip of 4%. The output torque of the machine at full load is  (A) 1.66 Nm (B) 95.50 Nm (C) 99.47 Nm (D) 624.73 Nm

Last Answer : A 400 V, 15 kW, 4-pole, 50 Hz, Y-connected induction motor has full load slip of 4%. The output torque of the machine at full load is 99.47 Nm

Description : If non-linear loads are connected to the power system, then (A) displacement power factor is same as the total power factor (B) displacement power factor is not equal to the total power ... factor is due to harmonic currents (D) total power factor is due to fundamental component of current

Last Answer : If non-linear loads are connected to the power system, then displacement power factor is not equal to the total power factor

Description : The connected load of a consumer is 2 kW and his maximum demand is 1.5 kW. The load factor of the consumer is (a) 0.375 (b) 0.75 (c) 1.33 (d) None of these  

Last Answer : a

Description : A building intended to be used for commercial purpose will be required to follow Energy conservation building code under Energy Conservation Act, 2001 provided its a) connected load is 120 kW and above b) ... and above c) connected load is100 kW and above or contract demand is 120 kVA and above

Last Answer : c) connected load is100 kW and above or contract demand is 120 kVA and above

Description : Network components are connected to the same cable in the _____ topology. 1) Star 2) Ring 3) Bus 4) Mesh 5) Mixed

Last Answer : Answer :2

Description : An AC circuit has a capacitive reactance of 30 ohms in addition to an inductive reactance of 40 ohms connected in series. What is the reactance of the circuit? A. 8.37 ohms B. 10.00 ohms C. 50.00 ohms D. 70.00 ohms

Last Answer : Answer: B

Description : In a star network each node (file server, workstations and peripherals) is connected to a central device called a _____: a) Bug b) Center c) Hub d) None of These

Last Answer : c) Hub

Description : Three identical resistors connected in star consume 5000 W. If the resistors are connected in delta across the same supply, the power consumed will be

Last Answer : Three identical resistors connected in star consume 5000 W. If the resistors are connected in delta across the same supply, the power consumed will be 15000 W

Description : A three-phase star -connected load is operating at a power factor angle ϕ  with ϕ being the angle between

Last Answer : A three-phase star -connected load is operating at a power factor angle ϕ  with ϕ being the angle between Phase voltage and phase current

Description : Three resistances of 3 Ω each are connected in delta. The value of the resistances in the equivalent star is : (A) 27 (B) 9 (C) 1.5 (D) 1 Ω

Last Answer : 9

Description : Why Delta Star Transformers are used for Lighting Loads?

Last Answer : A. For lighting loads, neutral conductor is must and hence the secondary must be star winding.This lighting load is always unbalanced in all three phases. To minimize the current unbalance in the primary we use delta winding in the primary. So delta / star transformer is used for lighting loads.

Description : Why Delta Star transformer Are Used For Lighting Loads?

Last Answer : For lighting loads, neutral conductor is must and hence the secondary must be star winding. and this lighting load is always unbalanced in all three phases. To minimize the current unbalance in the primary we use delta winding in the primary. So delta / star trformer is used for lighting loads.

Description : Why Delta Star Transformers are used for Lighting Loads?

Last Answer : For lighting loads, neutral conductor is must and hence the secondary must be star winding and this lighting load is always unbalanced in all three phases.  To minimize the current unbalance in the primary we use delta winding in the primary So delta / star transformer is used for lighting loads.

Description : If two electrical loads are connected in parallel with each other and each load draw 6 amps what is the current of the circuit?

Last Answer : 12 Amperes is.

Description : Which of the following statements represents the main difference between a relay and a contactor? A. Contactors control current and relays control voltage. B. A relay is series connected and a contactor ... loads than relays. D. Contactors are made from silver and relays are made from copper.

Last Answer : Answer: C

Description : In a D.C. 3-wire distributor using balancers and having unequal loads on the two sides (a) both balancers run as generators (b) both balancers run as motors (c) balancer connected to lightly- loaded side runs as a motor (d) balancer connected to heavily- loaded side runs as a motor

Last Answer : (c) balancer connected to lightly- loaded side runs as a motor

Description : (A) Tertiary carbocations are generally formed more easily than primary carbocations. (R) Hyperconjugation as well as inductive effect due to addition

Last Answer : (A) Tertiary carbocations are generally formed more easily than primary carbocations. (R) Hyperconjugation as ... A) is incorrect but (R) is correct.

Description : (A) Inductive and electromeric effects require polar nature in the molecule. (R) Polar nature in inductive effect is a must but not necessarily in ele

Last Answer : (A) Inductive and electromeric effects require polar nature in the molecule. (R) Polar nature in inductive ... (A) is incorrect but (R) is correct.

Description : In a three-phase system, when the loads are perfectly balanced, the value of neutral current is equal to: A. Zero B. One-third of the maximum value C. Two -third of the maximum value D. The maximum value

Last Answer : In a three-phase system, when the loads are perfectly balanced, the value of neutral current is equal to: Zero

Description : An R.C.C. roof slab is designed as a two way slab if (A) It supports live loads in both directions (B) The ratio of spans in two directions is less than 2 (C) The slab is continuous over two supports (D) The slab is discontinuous at edges

Last Answer : Answer: Option B

Description : Assertion A : The load factor for live load is greater than that for dead load. Reason R : The live loads are more uncertain than dead loads. Select your answer based on the coding system given below: (A) Both A ... explanation of A (C) A is true but R is false (D) A is false but R is true

Last Answer : Answer: Option A

Description : The beds which have a gentle upstream dip will be_______ to the resultant force (R), hence can provides the best resistance to withstand the stresses or loads acting in the area. (A) Parallel (B) Perpendicular (C) None of these 

Last Answer : (B) Perpendicular  

Description : A 3-phase voltage source inverter operates in 180° conduction mode with a star connected resistive load. If input dc voltage is 100 V, then the peak to peak output line voltage is :

Last Answer : A 3-phase voltage source inverter operates in 180° conduction mode with a star connected resistive load. If input dc voltage is 100 V, then the peak to peak output line voltage is : 200 V

Description : A 3-phase star-connected 75 MVA, 25 kV 3-phase synchronous generator has a synchronous reactance of 1.0 p.u. The per unit value to a 90 MVA base and 30 kV is (A) 2/15 p.u. (B) 5/6 p.u. (C) 1.0 p.u. (D) 1.2 p.u.

Last Answer : A 3-phase star-connected 75 MVA, 25 kV 3-phase synchronous generator has a synchronous reactance of 1.0 p.u. The per unit value to a 90 MVA base and 30 kV is 5/6 p.u.

Description : A meter whose constant is 600 revolutions/kWh makes 5 revolutions in 20 seconds. Calculate the load in kW. (1) 0.5 kW (2) 1 kW (3) 1.5 kW (4) 2 kW  

Last Answer : 1.5 kW 

Description : Qualitative research is often exploratory and has all of the following characteristics except: a. It is typically used when a great deal is already known about the topic of interest b. It ... hypotheses and develop theory about phenomena in the world d. It uses the inductive scientific method

Last Answer : a. It is typically used when a great deal is already known about the topic of interest

Description : A resistor of value R/2 is connected in parallel with a resistor of value R/3. The voltage drop across the parallel combination is V. The total current supplied by the voltage source is: w) 2 V/R (read: 2 V over R) x) 3 V/R (read: 3 V over R) y) 4 V/R (read: 4 V over R) z) 5 V/R (read: 5 V over R)

Last Answer : ANSWER: Z -- 5 V/R

Description : Why are generators rated in kVA not in kW ?

Last Answer : Because It's rating of generator kva is apparent power. Kw is active power which we use. And one is kvar reactive power.

Description : The corona loss of a 3-phase transmission line is 100 kW at 60 kV/phase and 25 kW at 50 kV/phase. The disruptive critical voltage is (A) 40 kV (B) 43.6 kV (C) 49.6 kV (D) 50 kV

Last Answer : The corona loss of a 3-phase transmission line is 100 kW at 60 kV/phase and 25 kW at 50 kV/phase. The disruptive critical voltage is 40 kV

Description : The maximum demand of consumer is 2 kW and his daily energy consumption is 20 units. Its Load Factor is (1) 10.15% (2) 41.6 % (3) 50 % (4) 60% 

Last Answer : Total maximum demand of energy in a day = 2kw*24= 48 units Consumer consumption is 20 units . Load factor = (number of units utilizing)/(total max. demand)      = 20/48 = 41.6%

Description : One 200 KVA transformer has an iron loss of 1 KW and full load Cu loss of 2 KW. Its load KVA corresponding to maximum efficiency is:  (A) 100 KVA (B) 141.4 KVA (C) 50 KVA (D) 200 KVA 

Last Answer : 100

Description : A 150 kW electric motor has an efficiency of 92 %, when it operates at full load. Calculate the losses in the machine.  (A) 92 kW (B) 150 kW (C) 163 kW (D) 13 kW 

Last Answer : efficiency  -output /input * 100 150/0.92----------163(input) losses-----(163--150)  ---------13kw.

Description : Two D.C. machines 500 kW each are tested by Hopkinson testing method. The power input would be ___________.

Last Answer : Two D.C. machines 500 kW each are tested by Hopkinson testing method. The power input would be 100 kW.

Description : The apparent power drawn by an A.C. circuit is 10 kVA and active power is 8 kW. The reactive power in the circuit is?

Last Answer : The apparent power drawn by an A.C. circuit is 10 kVA and active power is 8 kW. The reactive power in the circuit is 6 kVAR.

Description : In an AC. circuit, a low value of kVAR compared with kW indicates?

Last Answer : In an AC. circuit, a low value of kVAR compared with kW indicates high power factor.

Last Answer : A heater is rated as 230 V, 10 kW, A.C. The value 230 V refers to r.m.s. voltage.

Description : In a three phase transformer, if the primary side is connected in star and secondary side is connected in delta, what is the angle difference between phase voltage in the two cases. (A) delta side lags by -30°. (B) star side lags by -30°. (C) delta side leads by 30°. (D) star side leads by -30°.

Last Answer : Ans: C This is vector group and has +30° displacement. Therefore, delta side leads by +30°.

Description : A three-phase transformer, connected in star-delta, is composed of three single-phase transformers, each rated 127/ 13.2 kV. The line-to-line voltage ratio for the three-phase transformer is: A) 220 / 13.2 kV B) 127 / 13.2 kV C) 127 / 220 kV D) 220 / 220 kV

Last Answer : A three-phase transformer, connected in star-delta, is composed of three single-phase transformers, each rated 127/ 13.2 kV. The line-to-line voltage ratio for the three-phase transformer is: 220 / 13.2 kV 

Description : In a three phase transformer, if the primary side is connected in star and secondary side is connected in delta, the angle difference between phase voltage in the two cases will be: (A) delta side will lag by -30° ... will lag by -30° (C) delta side will lead by 30° (D) star side will lead by -30°

Last Answer : In a three phase transformer, if the primary side is connected in star and secondary side is connected in delta, the angle difference between phase voltage in the two cases will be: delta side will lead by 30° 

Description : In a certain three -wire Y -connected generator, the phase voltages are 2 kV. The magnitudes of the line voltages will be: A. 2,000 V B. 6,000 V C. 666 V D. 3,464 V

Last Answer : In a certain three -wire Y -connected generator, the phase voltages are 2 kV. The magnitudes of the line voltages will be: 3,464 V

Description : Briefly explain how the power factor of an inductive circuit can be improved.

Last Answer : As we know that power factor should be corrected to ensure that the current supplied is cost friendly. Meaning the power factor should be around one but not greater than one(0.8-0.9) in a ... an inductive circuit due to the inductive reactance which oppose the change of current in the ac circuit. 

Description : Explain the working of inductive proximity sensor. State any two applications.

Last Answer : Proximity sensors are input devices that detect presence of an object without physical contact. Internal construction of inductive proximity switch is as shown in figure. It consists of a ... Applications: 1) gear teeth sensing 2) RPM measurement 3) Object counting 4) Obstacle detection.

Description : A 200 V, 50 Hz inductive circuit takes a current of 10 A at 30 degree lagging pf, what is the inductive reactance of the circuit?  (A) 17.8 Ω (B) 100 Ω (C) 178 Ω (D) 10 Ω 

Last Answer : D