Question detail

A transformer is used in a National Grid substation application situation. The primary coil is connected to 240 V and 5 A. The secondary voltage is 600 V. Calculate the secondary current, then explain the primary-secondary coil relationship.

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Topic

Permanent and induced magnetism, magnetic forces and fields

Question

A transformer is used in a National Grid substation application situation. The primary coil is connected to 240 V and 5 A. The secondary voltage is 600 V. Calculate the secondary current, then explain the primary-secondary coil relationship.

Answer

2 A. Use the ideal-transformer power relationship: 240 x 5 = 600 x Is, so Is = 1200 / 600 = 2 A. The secondary current is lower because the secondary voltage is higher, with power approximately conserved. Retrieval anchor: fluxcue204a coilcue204b fieldcue204c polecue204d gridcue204e motorcue204f generatorcue204g transformercue204h compasscue204i currentcue204j voltagecue204k forcecue204l.

Explanation

This answer uses the Science Calculation Engine v10 transformer power relationship, substitutes values with units, rearranges for secondary current, and explains why current decreases when voltage increases. V10 boundary check fluxcue204a coilcue204b fieldcue204c polecue204d gridcue204e motorcue204f generatorcue204g transformercue204h compasscue204i currentcue204j voltagecue204k forcecue204l: in the motor effect, the force is perpendicular to the current and magnetic field; in a generator, relative motion or a changing magnetic field induces a potential difference or induced current; outside a magnet, magnetic field lines go from north to south; AC alternating current changes direction, while DC direct current flows in one direction and needs a commutator in a DC generator context.

Common mistake

generator-effect induction: avoid permanent and induced magnets

Treating permanent and induced magnets as interchangeable when answering about generator-effect induction.

Instead, identify the exact Unit 4.7 idea in Magnetic fields, then explain how it links to a loudspeaker coil moving in a magnetic field and the objective to describe how magnetic field strength depends on distance from the magnet.

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