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1) Hysteresis loop in case of magnetically hard materials is more in shape as compared to magnetically soft materials a. circular b. triangular c. rectangular d. none of the above
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2) A keeper is used to_____________? a. change the direction of magnetic lines b. amplify flux c. restore lost flux d. provide a closed path for flux
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3) The uniform magnetic field is______________? a. the field of a set of parallel conductors b. the field of a single conductor c. the field in which all lines of magnetic flux are parallel and equidistant d. none of the above
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4) The change of cross-sectional area of conductor in magnetic field will affect______________? a. reluctance of conductor b. resistance of conductor c. A. and B. both in the same way d. none of the above
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5) The magneto-motive force is______________? a. the voltage across the two ends of exciting coil b. the flow of an electric current c. the sum of all currents embraced by one line of magnetic field d. the passage of magnetic field through an exciting coil
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6) A certain amount of current flows through a ring-shaped coil with fixed number of turns. How does the magnetic induction B varies inside the coil if an iron core is threaded into coil without dimensional change of coil ? a. Decreases b. Increases c. Remains same d. First increases and then decreases depending on the depth of iron in¬sertion
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7) What will be the magnetic potential difference across the air gap of 2 cm length in magnetic field of 200 AT/m ? a. 2 AT b. 4 AT c. 6 AT d. 10 AT
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8) The initial permeability of an iron rod is________________? a. the highest permeability of the iron rod b. the lowest permeability of the iron rod c. the permeability at the end of the iron rod d. the permeability almost in non-magnetised state
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9) The magnetic reluctance of a material______________? a. decreases with increasing cross sectional area of material b. increases with increasing cross-sec-tional area of material c. does not vary with increasing cross-sectional area of material d. any of the above
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10) In a simple magnetic field the strength of magnet flux_______________? a. is constant and has same value in energy part of the magnetic field b. increases continuously from initial value to final value c. decreases continuously from initial value to final value d. first increases and then decreases till it becomes zero
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