With a secondary transformer output of 1,320 watts and a primary input of 1,800 watts, calculate the efficiency of the transformer. kothari chapter 3 question 3.10 practice problems question is based on the p.u. If the primary voltage is 240 V, find the secondary voltage. Problem 1. SOLVED PROBLEMS .

Learners examine how the load resistance connected to the secondary coil of a transformer affects the primary current. If its secondary winding is connected to a load whose resistance and inductive reactance are 4.25 and 3 , determine the secondary voltage and the power consumed by load (neglect no-load current). In conjunction with Equation 1, one can understand that in a transformer the ratio. T-shaped transformer equivalent circuit. Students solve practice problems on voltage, current, and impedance matching. Numerical Response 7. value of load current. = Output I nput 100 = 1320 1800 100 = 73.33 = O u t p u t I n p u t 100 = 1320 1800 100 = 73.33 9. SOLVED PROBLEMS. A transformer is used to step a potential difference of 230 V down to 10 V. The secondary coil has 60 turns. Calculate the number of turns of the primary coil. Solution: Vp = 230 V. Vs =10V. Ns=60. Np = ? => Np = (Vp/Vs). Ns = (230/10). 60 = 1380 turns. Transformers are almost 100% efficient. G. File Description: GATE Problem Solving Strategy; GATE 2017 to 2021 (Made Easy) GATE 2017 to 2021 (GATEFORUM) GATE 2017 by ACE; ACE PreGATE 2016 to 2020; Solved Problems on Single Stage Transistor Amplifiers. Power factor at primary terminals: cos(9.58 ) = 0.9861 lagging . a professional engineer & blogger from Andhra Pradesh, India. this question is taken from book electric machine by I.J nagarath & D.P. The secondary voltage is given by 250V, determine the primary voltage. The line has a reactance of 8% on base of 20MVA, 66 KV. If the primary coil has 600 turns, how many turns should be on the secondary coil? b) % of total bank current drawn by each transformer c) maximum bank load that can be handled without overloading either transformer Example 12-2 Solution (1) Lesson 12_et332b.pptx 10 a) Rated current of both transformers Transformer A: 100 kVA Transformer B: 200 kVA b) Percent current drawn by each transformer Convert %Z to actual ohms. Example 3: The resistances and leakage reactances of a 30-kVA, 60-Hz, 2400-V:240-V distribution transformer are . Input and output voltage of a transformer can be found by the following equations. Vp = 150 V. Example 2 R 2. Hence, the core Categories. Notes and Video Materials for Engineering in Electronics, Communications and Computer Science subjects are added. a) Determine the secondary voltage if the secondary circuit is open and the primary voltage is 120 V. Solution: RMS value of emf induced in Therefore, follow the steps listed for Case 1 to nd the primary line currents. In the circuit given in Fig.1, the transformer T 1 is a three-phase, D-Y connected transformer bank, composed of the above three single-phase identical transformers. Find : (i) the mean load current (ii) the r.m.s. The collector load is 1 k. 1. =. The number of primary and secondary windings is 60 and 100 respectively. Transformer 2: The linear dimensions are times of transformer 1. If the current in the primary coil is 4 Ampere, then what is the the current in the secondary coil.

Calculate the generated e.m.f? oppposite of your defined polarity.) A transformer cannot necessarily be connected to any arbitrary voltage or in an arbitrary fashion. In working with a transformer, special care must be taken for correct connection of its primary and secondary to the outside circuits. Ideal Transformer Example Problem 1. The primary winding of a transformer has 1000 turns. "A blog to support Electronics, Electrical communication and computer students". PROBLEMS.

5 DC Generator Problems with Solution Part 1. P lines =. Using, Vp/Vs=Np/Ns => Np = (Vp/Vs). 1.

removes the need for the ideal transformer. Losses In Transformer: Core / Iron Losses. For a practical two winding transformer, the knowledge of approximate equivalent circuit is of utmost importance in order to predict its performance. Solved Problems On Zener Diode. Known : Primary coil (NP) = 1200 loops. Follow below links to download MCQ Set. Assume ac to be nearly one. Problem 2.16 The core length of the second transformer is is 2 times that of the rst, its core area of the second transformer is twice that of the rst, and its volume is 2 2 times that of the rst. Primary winding current is . 2.

The numerical evaluation is based on Center Line Average (CLA) method. SOME QUICK POINTS FOR SOLVING PROBLEMS ON 3-PH TRANSFORMERS WITH UNBALANCED LOADS3 becomes exactly similar to Case 1. P load =. PROBLEM DESCRIPTION The shell-type transformer under analysis consists of two concentric coils wound around the cores central limb. Example 1: Solution: For maximum power transfer, the load resistance (referred to the primary) must be equal to the source resistance. (a) Derive the equation of balance of a Schering Bridge. Solved Problems On Rectifiers. - From the above equation force can be solved as a function of the flux and the mechanical terminal Primary in , Secondary in , Unbalanced load in Say, the transformer rating is 4 KV / 400 V . Worked example (numerical) using the Transformer equation A transformer is used to step a potential difference of 230 V down to 10 V. The secondary coil has 60 turns. Re-calculate the load voltage, load power, wasted power, and overall efficiency of Current flows in one dot and out the other. M = mutual inductance in k = coefficient of coupling between two inductances L. 1. and L. 2 = values of the two inductances. I'm Gopal Krishna. Basic electronics Solved problems Sasmita. % Voltage Regulation = [ { (No Load Voltage Full Load Voltage) / Full Load voltage} x 100] % Voltage Regulation = [ { (240V 230V) / 230} x 100] % Voltage Regulation = 4.347%. R 1. In the one-line diagram below, the impedance of various components in a power system, typically derived from their nameplates, are presented. At no load: transformer 1. 2. The test problem considered in the present study concerns the equivalent circuit of the idealized single-phase shell-type transformer described in [3]. X l1. The A synchronous generator and a synchronous motor each rated 20MVA, 12.66KV having 15% reactance are connected through transformers and a line as shown in fig. Transformers are basically of two types i.e; Step up transformer and step down transformer. Lets understand the concept of per unit system by solving an example. FOURIER SERIES MOHAMMAD IMRAN JAHANGIRABAD INSTITUTE OF TECHNOLOGY [Jahangirabad Educational Trust Group of Institutions] www.jit.edu.in MOHAMMAD IMRAN SEMESTER-II TOPIC- SOLVED NUMERICAL PROBLEMS OF FOURER SERIES. When a transformer is loaded with a constant primary voltage , the secondary voltage decreases for lagging power factor load, and increases for leading pf load because of its internal resistance and leakage reactance . Example 1: Suppose a transformer has a no load voltage of 240 volts and a full load voltage of 230 volts. Important Questions of Transformer.

All the MCQs are solved. Answer: Because electric power must be the same in both coils, the following relationship must be true. Example 1. Secondary coil (NS) = 1000 loops. Explore how to use the transformer formula to solve problem associated with electrical transformers . Np = ? Solution: Given: Np = 60, N s = 100. Solution : Q5. Rearranging the equation we A 50-Hz, 90-kVA, 3800/220-V, single-phase transformer has h = j4.5 and = j0.02 the high and low sides leakage reactances, respectively. This constant is called volts per turn and determines how many volts there are per each turn of either the primary or the secondary winding. Linear loads such as incandescent lights draw current equally throughout the waveform. Harmonics can cause computer equipment to lock up or cause the data to become garbled as well as causing transformers, motors, and neutral lines to overheat. In a given transformer for given applied voltage, losses which remain constant irrespective of load changes are 23. A common method of cooling a power transformer is 24. The no load current in a transformer lags behind the applied voltage by an angle of about In this lesson some typical problems on transformer are solved with emphasis on logical steps involved.

Per Unit System Practice Problem Solved For Easy Understanding. A shunt generator delivers 450 A at 230 V and the resistance of the shunt field and armature are 50 and 0.03 respectively. The losses that occur inside the core; Hysteresis Loss X l2 In a transformer for a doorbell, 115 V alternating current is to step-down to 24.0 V alternating current.

60 = 1380 turns. An alternating voltage, when applied to the primary of a transformer, produces an alternating magnetic field which induces EMF in the secondary windings.

A 400 kVA transformer has a primary winding resistance of 0.5 ohm and a secondary winding resistance of 0.001 ohm.

Frequency is 50 Hz. A full-wave rectifier uses two diodes, the internal resistance of each diode may be assumed constant at 20 . Amplifier (10) Amplitude Modulation (18) Solution: Vp = 230 V. Vs =10V. Non-linear loads such as switching power supplies draw current only at the peaks of the wave.

E load =. The produced magnetic flux is alternating in nature and lags the applied voltage by 90 0. Download 100 plus solved MCQs of Electrical Transformer. the transformers are rated 20MVA,12.66/66KV and 66/12.66KV with leakage reactance of 10% each. Ns = (230/10). 1.2.4 Load Sharing between Two Transformers in Parallel Having Equal Voltage Ratio 11 Solved Examples 12 Supplementary Problems 41 2. 1. If the power factor of the load is 0.85, determine the efficiency of the transformer (i) on full load and (ii) on half load. Complete set of Video Lessons and Notes available only at http://www.studyyaar.com/index.php/module/107-single-phase-transformerUnderstanding the Problem, Basic electronics Solved problems Sasmita. 1 ) Suppose that a body is being pulled up by 20 m along a rough inclined plane with constant speed. Example 2 . Figure 2. Hey Engineers, welcome to the award-winning blog,Engineers Tutor. [CORRECTION] final answer is 16.92 NOT 19.92. If a signal of 500 mV is applied between emitter and base, find the voltage amplification. Find out the efficiency with which the force raised the mass. DC MACHINES AND TRANSFORMERS LECTURE NOTES Dr. P Sridhar Professor & Head types of starters, numerical problems; Losses and efficiency: Types of losses, calculation of efficiency, condition for maximum efficiency. Now, suppose we were to use a pair of perfectly efficient 10:1 transformers to step the voltage up for transmission, and back down again for use at the load. Numerical problems for efficiency calculation. n is the number of turns Examples precede the problems. Power . 3. The turns ratio captures all the effects Circuit Model of Non-ideal Transformers Lesson 9_et332b.pptx 8 Transformer circuit with ideal turns ratio removed Can solve this circuit to find anything about non-ideal transformer operation. Basic electronics Solved problems Sasmita. Laminations and core material thickness are same for Calculate the number of turns of the primary coil. 2.

L=n. EXAMPLE 3: A 2200/500 V, single-phase transformer has the following winding resistances and reactances: R 1 = 0.5 , R 2 = 0.02 , X 1 = 3.75 , and X 2 = 0.05 . The transformer formula is given by, V p / V s = N p / N s. Vp = Np / N s Vs = 60 / 100 x 250. Since the voltage applied to the second transformer is twice that of the rst, the ux densitities will be the same. V s = 250V. Transformer Collection of Solved Problems Transformer Task number: 1548 A transformer has 500 turns of the primary winding and 10 turns of the secondary winding.

Solved Examples. The transfer function of the LVDT along with its interface circuitry is highly dependent on the interface circuitry. Watch Now 24 18.4k Q1. Ns=60. Z 01 = Equivalent Impedance of transformer from primary side; Z 02 = Equivalent Impedance of transformer from Secondary side; Input & Output Voltage Equations. The mass is 15 kg and the angle of the incline is 45. A common base transistor amplifier has an input resistance of 20 and output resistance of 100 k. A transformer has primary coil with 1200 loops and secondary coil with 1000 loops. For this problem we only need the number of turns (N) and voltage (V). Basic electronics Solved problems By Sasmita January 9, 2020. Transformer is an electrical device that makes the transfer of energy by forming inductive coupling between the winding of its circuits. [PDF] 100+ Solved MCQs on Transformer.

\$\begingroup\$ You defined E1 as positive when current flows out of the left dot. Therefore when E1 is positivve (current out of left dot) then current flows into right dor which makes E2 negative (i.e. KVA rating of the transformer is 450 KVA. The task now is to normalize these values using a common base. A brief quiz completes the activity. The transformers Regulation is calculated as follows. Next, follow the steps listed below: 1. FOURIER SERIES MOHAMMAD IMRAN SOLVED PROBLEMS OF FOURIER SERIES BY MOHAMMAD IMRAN The iron loss is 2.5 Kw and the primary and secondary voltages are 5 kV and 320 V respectively. \[\frac{V}{N}=\frac{{{V}_{1}}}{{{N}_{1}}}=\frac{{{V}_{2}}}{{{N}_{2}}}\] is a constant. The transformer r.m.s. (Reoord your answer to 3 significant digits) Question: Numerical Response 7. There is a constant frictional force of 42 N opposing the motion. Then a = 400 4000 = 1 10. Primary winding voltage is . Give the emf equation of a transformer and define each term Emf induced in primary coil E1 = 4.44 fmN1 volt Emf induced in secondary coil E2 = 4.44fmN2 volt Where f is the frequency of AC input m is the maximum value of flux in the core N1, N2 are the number of secondary voltage from centre tap to each end of secondary is 50 V and load resistance is 980 . EMF equation of transformers lets you calculate the RMS values of induced voltages in the primary and secondary windings of a transformer.