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MCQOPTIONS
This section includes 2670 Mcqs, each offering curated multiple-choice questions to sharpen your Railways knowledge and support exam preparation. Choose a topic below to get started.
| 651. |
Surge impedance of a transmission line is |
| A. | independent of its length |
| B. | dependent of its length |
| C. | independent on its temperature |
| D. | none of the above |
| Answer» B. dependent of its length | |
| 652. |
Which of the following techniques is used for the measurements of [a] [c] high frequency voltages? |
| A. | Peak voltmeter |
| B. | Series resistance micro-ammeter |
| C. | Resistance potential divider |
| D. | All of these |
| Answer» B. Series resistance micro-ammeter | |
| 653. |
A booster is connected in |
| A. | series with the feeder |
| B. | parallel with the feeder |
| C. | both [a] and [b] are correct |
| D. | none of these |
| Answer» B. parallel with the feeder | |
| 654. |
In case of Impulse Thermal break down of solid insulating materials, the critical electric field is proportional to |
| A. | critical absolute temperature |
| B. | square of critical absolute temperature |
| C. | square of Ty |
| D. | none of these |
| Answer» D. none of these | |
| 655. |
A differential relay responds to |
| A. | algebraic difference of two or more similar electrical quantities |
| B. | vector difference of two or more similar electrical quantities |
| C. | algebraic difference between two currents |
| D. | algebraic difference between two voltages |
| Answer» C. algebraic difference between two currents | |
| 656. |
In order to improve the voltage profile of the line compensation is resorted by providing |
| A. | capacitors at the receiving end |
| B. | reactors at the receiving end |
| C. | resistors at the receiving end |
| D. | none of these |
| Answer» B. reactors at the receiving end | |
| 657. |
Series capacitor is used in a transmission line to |
| A. | compensate the voltage drp |
| B. | reduce line loss |
| C. | limit short circuit current |
| D. | improve load power factor |
| Answer» B. reduce line loss | |
| 658. |
The conductor connecting consumer's terminals to the distributor is called the |
| A. | feeder |
| B. | distributor |
| C. | service main |
| D. | none of the above |
| Answer» D. none of the above | |
| 659. |
The change in excitation in an alternator connected to an infinite line provides a corresponding change in |
| A. | terminal voltage |
| B. | speed of rotor |
| C. | power generated |
| D. | power factor |
| Answer» E. | |
| 660. |
In a transformer, the exciting current will be in phase quadrature with the impressed voltage provided? |
| A. | only the leakage impedance drop is ignored |
| B. | only the core loss is ignored |
| C. | both the leakage impedance drop and the core loss are ignored |
| D. | only the no-load copper loss is ignored |
| Answer» D. only the no-load copper loss is ignored | |
| 661. |
The voltage measurements using uniform spark gap are |
| A. | affected by dust particles |
| B. | affected by polarity of supply |
| C. | affected by temperature |
| D. | none of these |
| Answer» B. affected by polarity of supply | |
| 662. |
The insulation of the modem EHV lines is designed based on |
| A. | corona |
| B. | switching voltage |
| C. | lightening voltage |
| D. | all of these |
| Answer» B. switching voltage | |
| 663. |
If two synchronous generators connected in parallel loose synchronism, it will lead to |
| A. | stalling of generators |
| B. | wild fluctuations in current |
| C. | wild fluctuations in current and voltage |
| D. | None of these |
| Answer» D. None of these | |
| 664. |
Which of the following method or techniques can be used for the measurement of high [d] [c] voltages? |
| A. | Generating voltmeter |
| B. | Electrostatic voltmeter |
| C. | Peak voltmeter |
| D. | Half effect generators |
| Answer» B. Electrostatic voltmeter | |
| 665. |
AC network analyzer is employed for solving the problems of |
| A. | load flow |
| B. | load flow and stability |
| C. | load flow and short circuit |
| D. | load flow, stability and short-circuit |
| Answer» E. | |
| 666. |
In a minimum oil circuit breaker the oil is used |
| A. | to act as circuit breaking medium only |
| B. | for circuit breaking and providing insulation |
| C. | for providing insulation only |
| D. | for none of the above purposes |
| Answer» B. for circuit breaking and providing insulation | |
| 667. |
Consider the following statements: 1. Heat is generated in a nuclear reactor by fission of U-235 by neutron. 2. Percentage of U-238 in natural Uranium is around 0.71. 3. Plutonium is not a naturally occurring nuclear fuel. Which of the statements given above is/are correct? |
| A. | 1 only |
| B. | 2 and 3 only |
| C. | 1 and 3 only |
| D. | 1, 2 and 3 |
| Answer» D. 1, 2 and 3 | |
| 668. |
In a convergent-divergent steam nozzle, the flow is supersonic at which location? |
| A. | Entrance of the nozzle |
| B. | Throat |
| C. | Converging portion of the nozzle |
| D. | Diverging portion of the nozzle |
| Answer» C. Converging portion of the nozzle | |
| 669. |
Consider the following statements in respect of nozzles: 1. The nozzle efficiency is defined as the ratio of the actual enthalpy drop to the isentropic enthalpy drop between the same pressures. 2. Velocity coefficient is defined as the ratio of exit velocity when the flow is isentropic, to the actual velocity. 3. The included angle of divergence is usually kept more than \[20{}^\circ .\] Which of the statements given above is/are correct? |
| A. | 1 only |
| B. | 1 and 2 only |
| C. | 3 only |
| D. | 1, 2 and 3 |
| Answer» E. | |
| 670. |
How does entropy change when the super saturation occurs in a steam nozzle? |
| A. | The entropy decreases |
| B. | The entropy increases |
| C. | The entropy decreases and then increases |
| D. | The entropy increases and then decreases. |
| Answer» B. The entropy increases | |
| 671. |
An isentropic nozzle is discharging steam at the critical pressure ratio. When the back pressure is further decreased, which one of the following will take place? |
| A. | Nozzle flow decreases |
| B. | Nozzle flow increases |
| C. | Nozzle flow will first increase, reach a maximum and then decrease |
| D. | Nozzle flow will remain unaltered. |
| Answer» E. | |
| 672. |
What is the material of thick walled canisters in which nuclear waste is buried deep? |
| A. | Zirconium |
| B. | Lead |
| C. | Stainless steel |
| D. | Tin |
| Answer» D. Tin | |
| 673. |
Consider the following statements about reactors: 1. Candu reactor is a natural uranium fuelled, heavy water cooled and moderated reactor. 2. In a pressurized water reactor the coolant water boils in the core of the reactor 3. Liquid metal is preferred as a coolant in case of a homogeneous reactor. Which of the statements given above is/are correct? |
| A. | 1 only |
| B. | 2 only |
| C. | 1 and 3 only |
| D. | 1, 2 and 3 |
| Answer» E. | |
| 674. |
Which one of the following is the correct statement? Reheating of steam under ideal conditions takes place at constant |
| A. | Entropy |
| B. | enthalpy |
| C. | Pressure |
| D. | temperature |
| Answer» B. enthalpy | |
| 675. |
Which one of the following is correct? De Laval turbine is a |
| A. | Simple reaction turbine |
| B. | Simple impulse turbine |
| C. | Velocity compounded impulse turbine |
| D. | Pressure compounded impulse turbine |
| Answer» C. Velocity compounded impulse turbine | |
| 676. |
Consider the following statements in the context of high pressure boilers: 1. The tendency of scale formation is eliminated due to high velocity of water through tubes. 2. The heat transfer coefficient is increased by increasing the velocity of water through tubes. 3. The steam can he raised quickly to meet the variable load. Which of the statements given above are correct? |
| A. | 1 and 2 only |
| B. | 2 and 3 only |
| C. | 1 and 3 only |
| D. | 1, 2 and 3 |
| Answer» D. 1, 2 and 3 | |
| 677. |
In a steam power plant what is the outcome of regenerative feed heating? 1. Increase in specific output 2. Increase in cycle efficiency 3. Improved quality of exhaust steam 4. Reduced condenser load Select the correct answer using the code given below: |
| A. | 1 and 3 only |
| B. | 2 only |
| C. | 2 and 4 |
| D. | 1, 2 and 3 |
| Answer» D. 1, 2 and 3 | |
| 678. |
Match List-I (Name of Boiler) with List-II (Type) and select the correct answer using the rode given below the lists: List-I (Name of Boiler) List-II (Type) A. Stirling 1. Bent water tube B. Cochran 2. Once through flow C. Lancashire 3. Vertical fire tube D. Benson 4. Incline water tube 5. Horizontal fire tube Codes: |
| A. | A\[\to \]2, B\[\to \]5, C\[\to \]4, D\[\to \]1 |
| B. | A\[\to \]1, B\[\to \]3, C\[\to \]5, D\[\to \]2 |
| C. | A\[\to \]2, B\[\to \]3, C\[\to \]5, D\[\to \]1 |
| D. | A\[\to \]1, B\[\to \]5, C\[\to \]4, D\[\to \]2 |
| Answer» C. A\[\to \]2, B\[\to \]3, C\[\to \]5, D\[\to \]1 | |
| 679. |
Match List-I (Reactor) with List-II (Characteristic) and select the correct answer using the code given below the lists: List-I (Rector) List-II (Characteristic) A. Heterogeneous reactor 1. May not need moderator B. Candu reactor 2. Natural uranium fuelled and heavy water cooled C. Boiling water reactor 3. Fuel and moderator are at different phases D. Fast breeder reactor 4. Coolant water boils in the case of the reactor Codes: |
| A. | A\[\to \]3, B\[\to \]4, C\[\to \]2, D\[\to \]1 |
| B. | A\[\to \]1, B\[\to \]2, C\[\to \]4, D\[\to \]3 |
| C. | A\[\to \]3, B\[\to \]2, C\[\to \]2, D\[\to \]1 |
| D. | A\[\to \]1, B\[\to \]4, C\[\to \]4, D\[\to \]3 |
| Answer» D. A\[\to \]1, B\[\to \]4, C\[\to \]4, D\[\to \]3 | |
| 680. |
In a simple turbine, the nozzle angle at the entrance \[30{}^\circ .\] what is the blade speed ratio for maximum diagram efficiency? |
| A. | 0.25 |
| B. | 0.5 |
| C. | 0.433 |
| D. | 0.125 |
| Answer» D. 0.125 | |
| 681. |
What is the cause of reheat factor in a steam turbine? |
| A. | Reheating |
| B. | Superheating |
| C. | Super saturation |
| D. | Blade friction |
| Answer» E. | |
| 682. |
What is the purpose of moderator in a nuclear reactor? |
| A. | Moderate the fission temperature |
| B. | Reduce the speed of fast moving neutrons |
| C. | Reduce \[\beta \] and \[\gamma \] rays |
| D. | Absorb excess neutrons in the reactor |
| Answer» C. Reduce \[\beta \] and \[\gamma \] rays | |
| 683. |
An attemparator is used in some utility boilers: |
| A. | Ahead of super heater for initial superheating. |
| B. | For optimizing steam output from the generator |
| C. | To regulate steam pressure |
| D. | To control degree of superheat. |
| Answer» B. For optimizing steam output from the generator | |
| 684. |
Steam flows at the rate of 10 kg/s through a supersonic nozzle. Throat diameter is 50 mm. Density ratio and velocity ratio with reference to throat and exit are respectively 2.45 and 0.8. What is the diameter at the exit'? |
| A. | 122.5 mm |
| B. | 58 mm |
| C. | 70 mm |
| D. | 62.5 mm |
| Answer» D. 62.5 mm | |
| 685. |
Which one of the following is the purpose of the purpose of blow down in a boiler? |
| A. | To control drum level |
| B. | To control solid concentration in the boiler water |
| C. | To increase the steam temperature |
| D. | To lower the steam temperature |
| Answer» C. To increase the steam temperature | |
| 686. |
S.I unit for radioactivity is: |
| A. | Joule |
| B. | amu |
| C. | Curie |
| D. | Becquerel |
| Answer» E. | |
| 687. |
In Fluidized bed combustion velocity of fluid is proportion of(r = radius of the particle) as: |
| A. | \[\frac{1}{r}\] |
| B. | \[\frac{1}{\sqrt{r}}\] |
| C. | \[\sqrt{r}\] |
| D. | r |
| Answer» D. r | |
| 688. |
The function of the moderator in nuclear reactor is to: |
| A. | Stop chain reaction |
| B. | Reduce the speed of the neutrons |
| C. | Absorb neutrons |
| D. | Reduce temperature |
| Answer» C. Absorb neutrons | |
| 689. |
Which of the following thermal power plants will have the highest overall thermal efficiency? |
| A. | Steam power plant |
| B. | Gas turbine power plant |
| C. | Combined gas and steam power plant |
| D. | Diesel power plant |
| Answer» D. Diesel power plant | |
| 690. |
In the case of supersaturated steam flow through a nozzle, which of the following statements are correct? 1. Availability increases 2. Mass flow coefficient is greater than unity. 3. Nozzle velocity coefficient is less than unity. Select the correct answer using the codes given below: Codes: |
| A. | 1, 2 and 3 |
| B. | 1 and 2 |
| C. | 2 and 3 |
| D. | 1 and 3 |
| Answer» C. 2 and 3 | |
| 691. |
Consider an actual regenerative Rankine cycle with one open feed water heater. For each kg steam entering the turbine, m kg steam with a specific enthalpy of \[{{h}_{1}}\] is bled from the turbine. Specific enthalpy of water entering the heater is \[{{h}_{2}}.\] The specific enthalpy saturated liquid leaving the heater is equal to: |
| A. | \[m{{h}_{1}}-({{h}_{2}}-{{h}_{1}})\] |
| B. | \[{{h}_{1}}-m\,({{h}_{2}}-{{h}_{2}})\] |
| C. | \[{{h}_{2}}-m\,({{h}_{2}}-{{h}_{1}})\] |
| D. | \[m{{h}_{2}}-({{h}_{2}}-{{h}_{1}})\] |
| Answer» D. \[m{{h}_{2}}-({{h}_{2}}-{{h}_{1}})\] | |
| 692. |
The most commonly used moderator in nuclear power plants is: |
| A. | Heavy water |
| B. | concrete and bricks |
| C. | Steel |
| D. | graphite |
| Answer» E. | |
| 693. |
Attempting is: |
| A. | Reduction of steam pressure |
| B. | Reduction of steam temperature |
| C. | Discharge of flue gases at certain height |
| D. | Conditioning of disposable fluids for minimum pollution |
| Answer» C. Discharge of flue gases at certain height | |
| 694. |
If the enthalpy drops of moving blade and fixed blade of a stage in a reaction turbine are 9 and 11 kJ/kg respectively, then degree of reaction of stage is: |
| A. | 0.1 |
| B. | 0.45 |
| C. | 0.55 |
| D. | 1 |
| Answer» C. 0.55 | |
| 695. |
In reaction turbines, with reduction of inlet pressure: |
| A. | The blade heights increase as the specific volume of steam decrease. |
| B. | The blade heights increase as the specific volume of steam increases |
| C. | The blade heights decrease as the specific volume of steam increases |
| D. | The blade heights decrease as the specific volume of the steam decreases. |
| Answer» B. The blade heights increase as the specific volume of steam increases | |
| 696. |
In a simple impulse turbine, the nozzle angle at the entrance is \[30{}^\circ .\] what will be the blade-speed ratio for maximum diagram efficiency? |
| A. | 0.433 |
| B. | 0.25 |
| C. | 0.5 |
| D. | 0.75 |
| Answer» B. 0.25 | |
| 697. |
Consider the following characteristics: 1. High steam and blade velocities 2. Low steam and blade velocities 3. Low speeds of rotation 4. High carry-over loss Which of these characteristics are possessed by a simple impulse turbine? |
| A. | 1 and 2 |
| B. | 2 and 3 |
| C. | 1 and 4 |
| D. | 3 and 4 |
| Answer» D. 3 and 4 | |
| 698. |
Purpose of moderator in nuclear reactor is to: |
| A. | Slow down the neutrons produced in fission |
| B. | Reduce nuclear pollution |
| C. | Control the reactor temperature so that protons produced are less |
| D. | Moderate the steam pressure to slow down the chain reaction. |
| Answer» B. Reduce nuclear pollution | |
| 699. |
A sodium graphite reactor uses sodium: |
| A. | As coolant and graphite as moderator |
| B. | As moderator and graphite as coolant |
| C. | With graphite as moderator and water as coolant |
| D. | As moderator and sodium, graphite and water together as coolant. |
| Answer» B. As moderator and graphite as coolant | |
| 700. |
Consider the following statements: The purpose of reheating the steam in a steam turbine power plant is to 1. Increase specific output 2. Increase turbine efficiency 3. Reduce the turbine speed 4. Reduce specific steam consumption. Which of the statements are correct? |
| A. | 2 and 4 |
| B. | 1 and 3 |
| C. | 1, 2 and 4 |
| D. | 1, 3 and 4 |
| Answer» D. 1, 3 and 4 | |