Description : Which of the listed transformer uses a single winding to produce voltage transformation? A. Stepup transformers B. Stepdown transformers C. Autotransformers D. Isolation transformers
Last Answer : Answer: C
Description : Which of the following statements is true concerning stepdown transformer operation? A. The inductance on the primary side is the same as the inductance on the secondary side. B. The voltage to the primary ... . D. The voltage to the primary side is greater than the voltage from the secondary side.
Last Answer : Answer: D
Description : The function of a stepdown potential transformer is to reduce the load _____________. A. voltage and current B. voltage and increase line current C. current and increase line voltage D. power
Last Answer : Answer: B
Description : Which of the following statements identifies the difference between the primary windings and the secondary windings of a 2:1 stepdown transformer? A. The secondary windings have twice as much resistance ... primary windings. D. The secondary windings have half as many turns as the primary windings.
Description : The diagram shown in the illustration represents a/an _____________. EL-0082 A. stepup transformer B. magnetic amplifier C. autotransformer D. Scott-connected transformer
Last Answer : Answer: A
Description : When a transformer is used to step down voltage, the low voltage winding is _____________. A. part of the core B. the primary coil C. not insulated D. the secondary coil
Description : Which of the following statements is true concerning a stepdown transformer in an operating AC power circuit? A. Voltage and current will both be increased. B. Voltage and current will both be decreased C. Voltage decreases as current increases. D. Voltage increases as current decreases.
Description : On AC vessels, which of the following statements represents the most difficult problem involved in obtaining a DC potential suitable for use by computer components? A. A stepdown transformer is ... voltage must be rectified and made ripple free. D. Rectifiers cannot operate with voltage regulators.
Description : A load with an impedance of 440 ohms is connected across the secondary of the transformer illustrated. If the input voltage is 110 VAC and the step-up ratio is 10 to 1, what will be the primary current? EL-0055 A. 2.5 amps B. 25 amps C. 250 amps D. current cannot be determined with information given
Description : A load is connected to the secondary of the transformer illustrated and the current through the load is 10 amps. If the step-up ratio is 10 to 1 and the input voltage is 110 VAC, what will be the current flow through the primary? EL-0055 A. 1 amp B. 10 amps C. 100 amps D. 1000 amps
Description : The primary winding of a 220/6 V, 50 Hz transformer is energised from 110 V, 60 Hz supply. The secondary output voltage will be (A) 3.6 V. (B) 2.5 V. (C) 3.0 V. (D) 6.0 V.
Last Answer : (C) 3.0 V.
Description : A load with an impedance of 440 ohms is connected across the secondary of the device illustrated. If the input voltage is 110 VAC and the step-up ratio is 10 to 1, what will be the primary current? EL-0055 A. 2.5 amps B. 25 amps C. 250 amps D. current cannot be determined with information given
Description : A load is connected to the secondary of the device illustrated and the current through the load is 10 amps. If the step-up ratio is 10 to 1 and the input voltage is 110 VAC, what will be the current flow through the primary? EL-0055 A. 1 amp B. 10 amps C. 100 amps D. 1000 amps
Description : The most common source of excitation for synchronous motors is a/an ______________. A. stepup transformer B. half-wave rectifier C. DC supply D. AC supply
Description : If we give 2334 A, 540V on Primary side of 1.125 MVA step up transformer, then what will be the Secondary Current, If Secondary Voltage=11 KV?
Last Answer : A. As we know the Voltage & current relation for transformer-V1/V2 = I2/I1 We Know, VI= 540 V; V2=11KV or 11000 V; I1= 2334 Amps. By putting these value on Relation540/11000= I2/2334 So,I2 = 114.5 Amps
Last Answer : As we know the Voltage & current relation for transformer-V1/V2 = I2/I1 We Know, VI= 540 V; V2=11KV or 11000 V; I1= 2334 Amps. By putting these value on Relation540/11000= I2/2334 So,I2 = 114.5 Amps
Description : Relative to the secondary winding of a step-up transformer, the primary winding will have _____________. A. more turns B. fewer turns C. half as many turns D. twice as many turns
Description : 66 While conducting short-circuit test on a transformer the following side is short circuited A. High voltage side B. low voltage side C. primary side D. secondary side
Last Answer : B. Low voltage side
Description : The purpose of the automatic bus transfer shown in the illustration is to ___________. EL-0014 A. stepdown voltage to the lighting distribution panel B. provide emergency power to ... emergency switchboard from the main switchboard D. provide overcurrent protection to the lighting distribution panel
Description : In the illustrated circuit, if the input to leads 'B' and 'Y' was 24 VDC the output between 'A' and 'X' will be _________. EL-0069 A. 24 VDC B. 22.8 VDC, 24 VDC minus the 1.2 VDC voltage drop across two diodes C. undeterminable without knowing the turns ratio of the transformer D. 0 VDC
Description : The voltage at the reference electrode of the circuit shown in the illustration is applied to the input of a/an ______________. EL-0090 A. class A detector whose output drives an ... drives an 2-stage isolation transformer D. magnetic amplifier whose output controls a saturable reactor
Description : Increasing the load to the secondary windings of a transformer will cause a/an ____________. A. decrease in the primary voltage B. increase in the primary voltage C. decrease in the primary current D. increase in the primary current
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 : The purpose of a motor undervoltage protection device is to _____________. A. prevent high armature current when power is restored B. start the motor at a very low voltage C. trip the load off the motor in case of fire D. protect personnel from low voltage shocks
Description : If the illustrated device has a step-up ratio of 10 to 1 what voltage be measured at the secondary shortly after the primary of the device is connected to 110 volts DC with a current of 12 amps? EL-0055 A. 0 volts B. 110 volts C. 1000 volts D. 1100 volts
Description : In the illustration, if the device in figure 'A' has a step-up ratio of 10 to 1, what voltage should be measured at the secondary shortly after the primary of the device is connected to 110 volts DC? EL-0059 A. 0 volts B. 110 volts C. 11 volts D. 1100 volts
Description : If a transformer primary is energised from a square wave voltage source, its output voltage will be (A) A square wave. (B) A sine wave. (C) A triangular wave. (D) A pulse wave.
Last Answer : (A) A square wave.
Description : The stepup transformer increases?
Last Answer : The stepup transformer increases voltage.
Description : During short circuit test iron losses are negligible because A. The current on secondary side is negligible B. The voltage on secondary side does not vary C. The voltage applied on primary side is low D. Full-load current is not supplied to the transformer
Last Answer : C) the voltage applied on primary side is low
Description : A bolometer is (A) Used for the measurement of thermal radiation (B) An element which senses optical input and delivers thermal output (C) Both (A) & (B) (D) Neither (A) nor (B)
Last Answer : (C) Both (A) & (B)
Description : A device used in an electrical circuit to change alternating current to direct current, is known as a _____________. A. current transformer B. rectifier C. condenser D. shunt
Description : If output voltage is greater than input voltage, then transformer is A. step up B. step down C. faulty D. fatal
Last Answer : step up
Description : Transformers are used onboard ships with AC generators to _____________. A. change frequency B. increase power output to modulating frequency controllers C. decrease power output to modulating frequency ... D. permit higher voltage for electric motor operation and low voltage for lighting circuits
Description : Since the characteristics of the device shown in figure 'A' of the illustration includes a stable voltage and low current while operating, it can be suitably used in _____________. EL-0065 A. oscillators ... . class A and B amplifiers C. generator rectifier and filtering supplies D. all of the above
Description : Low horsepower, polyphase, induction motors can be started with full voltage by means of _____________. A. compensator starters B. autotransformer starters C. across-the-line starters D. primary-resistor starters
Description : The hook-on AC volt-ammeter consists essentially of a split-core and a rectifiertype instrument connected to the secondary winding of a _____________. A. potential transformer B. control transformer C. current transformer D. reactance transformer
Description : Transformer cores are laminated to reduce _____________. A. eddy currents B. secondary flux C. leakage flux D. all of the above
Description : The leads to the primary and the high-voltage secondary windings of a power transformer usually are of what color?
Last Answer : Primary leads-black; secondary leads red.
Description : In a tap changing transformer, the tappings are provided on (a) primary winding (b) secondary winding (c) high voltage winding (d) any of the above
Last Answer : (b) secondary winding
Description : The device in figure 'B' shown in the illustration can be used to control an AC load yet maintain its high gain by ______________. EL-0091 A. connecting the load to the output side of the ... connecting the load to the input side of the bridge D. reversing the current flow through the bias winding
Description : An operational amplifier, as used in today's consoles, has a calculated gain of 5. This means that when the input changes _____________. A. 5 volts, the output changes 10 volts B. 10 volts, the output changes 5 volts C. 2 volts, the output changes 10 volts D. 10 volts, the output changes 2 volts
Description : Basic operating characteristics of the operational amplifier such as gain and stability are the function of its _____________. A. differential input stage B. power output stage C. feedback circuit D. supply voltages
Description : Which unit holds data permanently? A) Input unit B) Secondary storage unit C) Output Unit D) Primary Memory Unit
Last Answer : Answer : B
Description : Which unit holds data temporarily? A) Input unit B) Secondary storage unit C) Output Unit D) Primary Memory Unit
Last Answer : Answer : D
Description : The central processing unit (CPU) consists of A) Input, output and processing B) Control unit, primary storage, and secondary storage C) Control unit, arithmetic-logic unit and primary storage D) Control unit, processing, and primary storage
Last Answer : Answer : C
Description : A memory in CPU that holds program instructions, input data, intermediate results and the output information produced during processing is __________ A. System B. Primary Memory C. Secondary Memory D. None of the above
Last Answer : B. Primary Memory
Description : The central processing unit (CPU) consists of a. Input, output and processing b. Control unit, primary storage, and secondary storage c. Control unit, arithmetic-logic unit and primary storage d. Control unit, processing, and primary storage
Last Answer : Control unit, arithmetic-logic unit and primary storage
Last Answer : c. Control unit, arithmetic-logic unit and primary storage