Sol_HW9

. What is the purpose of a discharge device used in conjunction with opening a highly inductive circuit?a) to minimize the possibility of damage to the circuits insulation as a result of a high induced voltage b) to minimize the possibility of endangering the life of the person opening the controlling switch c) to allow the magnetic field to gradually collapse, thus limiting the value of the self-induced ernf d) all of the above

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A freight elevator weighing 5000kg is to be lifted 20 meters in 3 minutes.  Calculate the horsepower of the motor required to do the job. A magnetic circuit has a flux of .75 Webers.  The magnetic force (Fm) applied to the circuit is 550 Amp-turns.  What is the reluctance (Rm) of the magnetic circuit? A magnetic circuit with a reluctance (Rm) of 1500 AT/Wb has a flux of 430 mWb.  What is the force magnetic (Fm) of this circuit? Hint: Rm = Fm/flux

An iron core 0.4 m long and 5 cm2is wound with 300 turns. When a current of 0.5A flows in the coil, how much is the inductance of the coil. Assume the core has a permeability of 2500.

Answer the following Questions Question-1 A coil of 1000 turns is wound on a laminated core of steel having a cross-section of 5 cm². The core has an air gap of 2 mm cut at right angle. a. What value of current is required to have an air gap flux density of 0.5 T? Permeability of steel may be taken as infinity. b. Determine the coil inductance.

A flux of 0.0016 Wb flows in a silicon sheet steel coil/core. The arrangement appears as shown below with the following dimensions: Ac = 0.0025 m? Core/gap area: Flux path length: le = 0.350 m lg = 0.0015 m N = 500 Air gap length: Number of turns: %3D A. What is the current, I, through the winding? B. What is the energy stored in the inductance? C. Assume that the current is given by i =9.75 sin (3147) A. What is the RMS voltage that would appear across the winding? D. Assume that the gap is removed from the arrangement with the flux path remaining at 0.350 m. For a flux of 0.0016 Wb, what is the inductance of the arrangement? E. What is the energy stored in the inductance with the gap removed?

A)The left hand rule for a coil is such that if you were to hold a coil in your left hand with your fingers pointing in the direction of the electron flow, your thumb would point in the direction of thea) electron flow b) flow lines c) face of the north pole d) none of the above. B) What is a magnetic flux line?a) It is the space around a magnet or the space in which the magnetic forces act.b) It is the magnetic force that has a definite direction at all points along a curved line from the north to south pole.c) It is the ability of a magnetic material to be easily magnetized.d) none of the above C)It is believed that a magnetic material is .........a) consists of a single large magnetic molecule b) is composed of many tiny magnetic molecules c) consists of a single non-magnetic molecule d) none of the above