36. A dielectric material is:
A. a good conductor
B. a good insulator
C. a poor conductor of electrostatic fields
D. a good conductor of magnetic fields
E. None of the above
37. A certain electromagnet has 1000 turns of wire. How much current must flow through the coil in order to generate an mmf of 100 ampere-turns?
A. 0.1 A
B. 1000 A
C. 10 A
D. 100 A
E. None of the above
38. If a load resistance is 1 kW, a stiff current source has a resistance of
A. At least 10 Ohm
B. Less than 10 Ohm
C. More than 100 k Ohm
D. Less than 100 k Ohm
E. None of the above
39. A flashlight battery has an internal resistance of 1W. For what values of load resistance does the flashlight battery appear stiff?
A. 60 Ohm
B. 50 Ohm
C. 100 Ohm or more
D. 10 Ohm
E. None of the above
40. The number of free electrons and holes in intrinsic semiconductor increases when the temperature
A. Decreases
B. Increases
C. Stays the same
D. 0°C
E. None of the above