Certificate In Control Transformer Manufacturing Business /30 0 Your Examination is Complete ! Certificate In Control Transformer Manufacturing BusinessOnline Examination Detail: Duration- 60 minutes. Number of Questions- 30. (Multiple Choice Questions). Maximum Marks- 100, Passing Marks- 40%. There is no negative marking. Candidate Details NameEmailPhone Number 1 / 301. Transformers are generally designed for ___________ A. one-time use B. off-site problem solving C. short-time use D. on-site problem solving 2 / 302. The equivalent resistance of the primary of a transformer having K= 5 and R1= 0.1 ohm when referred to secondary becomes.......ohm. A. 0.5 B. 0.02 C. 0.004 D. 2.5 3 / 303. What is the function of a breather in a transformer? A. To arrest flow of moisture when outside air enters the transformer B. To cool the transformer oil C. To provide oxygen inside the tank D. To cool the coils during reduced load 4 / 304. In a two-winding transformer, the e.m.f. per turn in secondary winding is always .......the induced e.m.f. power turn in primary. A. equal to K times B. equal to 1/K times C. equal to D. greater than. 5 / 305. What is the working principle of a Transformer? A. Transformer works on the principle of self induction B. Transformer works on the principle of mutual induction C. Transformer works on the principle of ampere law D. Transformer works on the principle of coulomb law 6 / 306. Which type of flux does transformer action need? A. Alternating electric flux B. Alternating magnetic flux C. Increasing magnetic flux D. Constant magnetic flux 7 / 307. In a transformer, the leakage flux of each winding is proportional to the current in that winding because A. Ohm’s law applies to magnetic circuits B. leakage paths do not saturate C. the two windings are electrically isolated D. mutual flux is confined to the core. 8 / 308. The main purpose of using core in a transformer is to A. decrease iron losses B. prevent eddy current loss C. eliminate magnetic hysteresis D. decrease reluctance of the common magnetic circuit. 9 / 309. In performing the short circuit test of a transformer A. high voltage side is usually short circuited B. low voltage side is usually short circuited C. any side is short circuited with preference D. none of the above. 10 / 3010. The purpose of the transformer core is to provide ____________ A. Low reluctance path B. High inductive path C. High capacitive path D. High reluctance path 11 / 3011. A transformer has negative voltage regulation when its load power factor is A. zero B. unity C. leading D. lagging 12 / 3012. Which of the following transformer, Buchholz’s relay can be fixed on? A. Welding transformers B. Oil cooled transformers C. Auto-transformers D. Air-cooled transformers 13 / 3013. A step-up transformer increases A. voltage B. current C. power D. frequency. 14 / 3014. The primary and secondary windings of an ordinary 2-winding transformer always have A. different number of turns B. same size of copper wire C. a common magnetic circuit D. separate magnetic circuits. 15 / 3015. Transformer core is generally made of ___________ A. Cannot be determined B. Can be made with any of the above method C. By stacking large number of sheets together D. Single block of core material 16 / 3016. In relation to a transformer, the ratio 20 : 1 indicates that A. there are 20 turns on primary one turn on secondary B. secondary voltage is 1/20th of primary voltage C. primary current is 20 times greater than the secondary current. D. for every 20 turns on primary, there is one turn on secondary. 17 / 3017. A transformer having 1000 primary turns is connected to a 250-V a.c. supply. For a secondary voltage of 400 V, the number of secondary turns should be A. 1600 B. 250 C. 400 D. 1250 18 / 3018. A transformer transforms A. frequency B. voltage C. current D. voltage and current 19 / 3019. Transformer cores are laminated in order to A. simplify its construction B. minimize eddy current loss C. reduce cost D. reduce hysteresis loss. 20 / 3020. Which of the following is not a basic element of a transformer ? A. core B. primary winding C. secondary winding D. mutual flux. 21 / 3021. The primary and secondary induced e.m.fs. E1 and E2 in a two-winding transformer are always A. equal in magnitude B. anti phase with each other C. in-phase with each other D. determined by load on transformer secondary. 22 / 3022. What is the current transformer? A. transformer used with an A.C. voltmeter B. transformer used with an A.C. ammeter C. transformer used with an D.C. voltmeter D. transformer used with an D.C. ammeter 23 / 3023. What is the thickness of laminations used in a transformer? A. 14 mm to 15 mm B. 25 mm to 40 mm C. 0.1 mm to 0.5 mm D. 4 mm to 5 mm 24 / 3024. Primary winding of a transformer ______________ A. Could either be a low voltage or high voltage winding B. Is always a high voltage winding C. Cannot be determined D. Is always a low voltage winding 25 / 3025. Transformer ratings are given in _____________ A. kVA B. HP C. kVAR D. kW 26 / 3026. What is the function of a transformer? A. Transformer is used to step down or up the AC voltages and currents B. Transformer is used to step down or up the DC voltages and currents C. Transformer converts DC to AC voltages D. Transformer converts AC to DC voltages 27 / 3027. Which of the following is not a part of transformer installation? A. Breather B. Conservator C. Exciter D. Buchholz relay 28 / 3028. Current transformers are __________________ A. parallel connected type of instrument transformers B. series connected type of instrument transformers C. parallel connected normal transformers D. series-parallel connected type of instrument transformers 29 / 3029. What is Transformer? A. Transformer is a device used to convert low alternating voltage to a high alternating voltage B. Transformer is a device used to convert alternating current to direct current C. Transformer is a device used to convert low alternating current to a high alternating current D. Transformers are used only for low alternating voltage 30 / 3030. In an ideal transformer, A. windings have no resistance B. core has no losses C. core has infinite permeability D. all of the above. Exit
