Magnetism and Electromagnetism What is the magnetomotive force (mmf) of a wire with 8 turns carrying three amperes of current? 240 At 2,400 At 2.4 At 24 At 240 At 2,400 At 2.4 At 24 At ANSWER DOWNLOAD EXAMIANS APP
Magnetism and Electromagnetism A coil of wire is placed in a changing magnetic field. If the number of turns in the coil is decreased, the voltage induced across the coil will Decrease Increase Remain Constant Be excessive Decrease Increase Remain Constant Be excessive ANSWER DOWNLOAD EXAMIANS APP
Magnetism and Electromagnetism A square cross-sectional magnet has a pole strength of 1 x 10 Wb and cross sectional area of 20 mm x 20 mm. What is the strength at a distance of 100 mm from the unit pole in air ? 633.8 N/Wb 6338 N/Wb 63.38 N/Wb 63380 N/Wb 633.8 N/Wb 6338 N/Wb 63.38 N/Wb 63380 N/Wb ANSWER DOWNLOAD EXAMIANS APP
Magnetism and Electromagnetism 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? Increases Decreases Remains same First increases and then decreases depending on the depth of iron in¬sertion Increases Decreases Remains same First increases and then decreases depending on the depth of iron in¬sertion ANSWER DOWNLOAD EXAMIANS APP
Magnetism and Electromagnetism Susceptibility is positive for ferromagnetic substances diamagnetic substances non-magnetic substances None of these ferromagnetic substances diamagnetic substances non-magnetic substances None of these ANSWER DOWNLOAD EXAMIANS APP
Magnetism and Electromagnetism What is the reluctance of a material that has a length of 0.07 m, a cross-sectional area of 0.014 m2, and a permeability of 4,500 Wb/At × m? 1 At/Wb 111 At/Wb 1111 At/Wb 11 At/Wb 1 At/Wb 111 At/Wb 1111 At/Wb 11 At/Wb ANSWER DOWNLOAD EXAMIANS APP
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