1 .		When the north poles of two bar magnets are brought close together, there will be [Hint]   no force   a downward force   a force of attraction   a force of repulsion
2 .		The direction of a magnetic field within a magnet is [Hint]   from south to north   from north to south   back to front   front to back
3 .		If the cross-sectional area of a magnetic field increased, but the flux remains the same, the flux density [Hint]   increases   decreases   remains the same   doubles
4 .		What is the magnetomotive force in a 75 turn coil of wire when there are 4 A of current through it? [Hint]   18.75 At   30 At   300 At   187 At
5 .		When a solenoid is activated, the force that moves the plunger is [Hint]   an electromagnetic field   a permanent magnetic field   varying voltage   a steady current
6 .		What is the flux density in a magnetic field in which the flux in 0.1m2 is 600 Wb? [Hint]   6,000 T   600 T   600 T   6 T
7 .		What is the flux density when the flux is 5.5 Wb and the cross-sectional area is 6 x 10-3 m2? [Hint]   91.7 T   917 T   91 T   9.7 T
8 .		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 x m? [Hint]   1111 At/Wb   111 At/Wb   11 At/Wb   1 At/Wb
9 .		What is the magnetomotive force (mmf) of a wire with 8 turns carrying three amperes of current? [Hint]   2,400 At   240 At   24 At   2.4 At
10 .		What is the reluctance of the circuit in problem 9 if the flux is 275Wb? [Hint]   0.0066 At/Wb   0.066 At/Wb   8,727 At/Wb   872 At/Wb
11 .		When the current through the coil of an electromagnet reverses, the [Hint]   direction of the magnetic field reverses   direction of the magnetic field remains unchanged   magnetic field expands   magnetic field collapses
12 .		An electromagnetic field exists only when there is [Hint]   an increasing current   decreasing current   voltage   current
13 .		For a given wirewound core, an increase in current through the coil [Hint]   reverses the flux lines   decreases the flux density   increases the flux density   causes no change in flux density
14 .		The ability of a material to remain magnetized after removal of the magnetizing force is known as [Hint]   permeability   reluctance   hysteresis   retentivity
15 .		The induced voltage across a stationary conductor in a stationary magnetic field is [Hint]   zero   reversed in polarity   increased   decreased
16 .		When the speed at which a conductor is moved through a magnetic field is increased, the induced voltage [Hint]   increases   decreases   remains constant   reaches zero
17 .		If the steel disk in a crankshaft position sensor has stopped with the tab in the magnet's air gap, the induced voltage [Hint]   increases   decreases   is zero   will remain constant
18 .		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 [Hint]   increase   decrease   remain constant   be excessive
19 .		A basic one-loop dc generator is rotated at 90 rev/s. How many times each second does the dc output voltage peak (reach maximum)? [Hint]   90   180   270   360
20 .		The voltage induced across a certain coil is 200 mv. A 120 resistor is connected to the coil terminals. The induced current is [Hint]   1.7 mA   16 mA   12 mA   120 mA
21 .		There is 900 mA of current through a wire with 40 turns. What is the reluctance of the circuit if the flux is 400 Wb? [Hint]   14,400 At/Wb   1,440 At/Wb   9,000 At/Wb   90,000 At/Wb
22 .		The induced voltage across a coil with 250 turns that is located in a magnetic field that is changing at a rate of 8 Wb/s is [Hint]   1,000 V   2,000 V   31.25 V   3,125 V
23 .		If a loop in a basic dc generator suddenly begins rotating at a faster speed, the induced voltage [Hint]   remains unchanged   reverses polarity   increases   decreases
24 .		The unit for reluctance is [Hint]   tesla   At/Wb   At/m   Wb
25 .		The unit for permeability is [Hint]   Wb/At x m   At/m   At/Wb   Wb