A coil of 600 turns is threaded by a flux of 8 x 10^-5 webers if this flux is reduced to 3 x 10^-5 webers in 0.015 seconds. The average induced e.m.f. is:
Correct answer: C. +2.0 volts
- A. -2.0 volts
- B. -3.0 volts
- C. +2.0 volts
- D. +2.5 volts
- E. +3.0 volts
Explanation
Emf = - N (dФ/dt)where number of turns are denoted by N, dФ is the change in flux and dt is the time interval.Change in flux = Final Flux - Initial FluxChange in flux = (3 × 10⁻⁵) - (8 × 10⁻⁵) WbChange in flux = - (5 × 10⁻⁵) Wbtime interval = 0.015 sectime interval = 15 × 10⁻³ secNumber of turns in coil = 600Putting all the values in formula.Emf = - 600 × (-(5 × 10⁻⁵)/15 × 10⁻³) VoltsEmf = 600 × (5 × 10⁻²/15 ) VoltsEmf = 600 × (10⁻²/3 ) VoltsEmf = 200 × 10⁻² VoltsEmf = 2 Volts
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Magnetic flux density and magnetic flux describe the strength of a magnetic field and the field passing through a surface. A charged particle moving through a magnetic field experiences a force perpendicular to its velocity and may follow circular or helical motion, depending on the angle between velocity and field.
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