IOCL Junior Operator MCQ Part-8 || IOCL Junior Operator General Science Questions and Answers71. How is oil circulated in oil filled cables?1 . Through external pumps 2 . Through channels or ducts in the cable 3 . Through a central reservoir 4 . Through a vacuum system Answer and SolutionAnswer: "Through channels or ducts in the cable "In oil filled cables, oil is circulated through channels or ducts provided in the cable. Discuss72. What is the role of oil under pressure in oil filled cables?1 . To provide additional insulation 2 . To prevent electromagnetic interference 3 . To cool the cable during operation 4 . To compress the layers of paper insulation and fill voids Answer and SolutionAnswer: "To compress the layers of paper insulation and fill voids "Oil under pressure compresses the layers of paper insulation and is forced into any voids that may have formed, eliminating voids and improving insulation. Discuss73. What is the voltage range for oil filled cables?1 . Up to 33 KV 2 . Beyond 230 KV 3 . From 66 KV to 230 KV 4 . Up to 66 KV Answer and SolutionAnswer: "From 66 KV to 230 KV "Oil filled cables can be used for higher voltages, ranging from 66 KV to 230 KV. Discuss74. How many types of oil filled cables are there?1 . Two 2 . Three 3 . Four 4 . Five Answer and SolutionAnswer: "Three "There are three types of oil filled cables: single-core conductor channel, single-core sheath channel, and three-core filler-space channels. Discuss75. What is a "Ground Fault" in a cable?1 . A current flow between two conductors 2 . A break in the cable’s insulation 3 . A current flow from the core of the cable to the lead sheath or earth 4 . A complete break in the cable’s conductor Answer and SolutionAnswer: "A current flow from the core of the cable to the lead sheath or earth "A ground fault occurs when the insulation of the cable breaks down, causing a flow of current from the core of the cable to the lead sheath or earth. Discuss76. What is a "Short Circuit Fault" in a cable?1 . A current flow from the core of the cable to the lead sheath 2 . A current flow between two conductors due to faulty insulation 3 . A break in the cable’s insulation 4 . A complete break in the cable’s conductor Answer and SolutionAnswer: "A current flow between two conductors due to faulty insulation "A short circuit fault occurs when the insulation between two conductors is faulty, causing a current to flow between them. Discuss77. What is the first step in identifying a ground fault in a multi-core cable?1 . Measure the insulation resistance of each core to earth 2 . Perform a loop test 3 . Check the cable’s physical condition 4 . Use a Wheatstone bridge Answer and SolutionAnswer: "Measure the insulation resistance of each core to earth "The first step in identifying a ground fault in a multi-core cable is to measure the insulation resistance of each core to earth. This helps to sort out the core that is earthed. Discuss78. What is the first step in identifying a short circuit fault in a multi-core cable?1 . Use a Wheatstone bridge 2 . Perform a loop test 3 . Measure the insulation resistance between cores 4 . Check the cable’s physical condition Answer and SolutionAnswer: "Measure the insulation resistance between cores "The first step in identifying a short circuit fault in a multi-core cable is to measure the insulation resistance between cores. This helps to sort out the cores that are shorted. Discuss79. Which type of test is used for locating ground and short circuit faults in cables?1 . Loop tests 2 . Insulation resistance tests 3 . Voltage tests 4 . Current tests Answer and SolutionAnswer: "Loop tests " Loop tests are used for locating ground and short circuit faults in cables. These tests can only be used if a sound cable runs along with the faulty cable. Discuss80. What principle do loop tests work on?1 . Ohm’s Law 2 . Kirchhoff’s Law 3 . Wheatstone bridge 4 . Faraday’s Law Answer and SolutionAnswer: "Wheatstone bridge " Loop tests work on the principle of a Wheatstone bridge. This setup allows the resistance of the fault to be connected in the battery circuit without affecting the result. Discuss123456789
