1. Which of the following is the only natural magnet?
A. Magnetite
B. Ebonite
C. Cobalt
D. Nickel
2. If the cross-sectional area of a magnetic field increases, but the flux remains the same, the flux density
A. increases
B. remains the same
C. doubles
D. decreases
3. An electromagnetic field exists only when there is
A. voltage
B. an increasing current
C. decreasing current
D. current
4. Which of the following cannot be used to make a magnet?
A. Cobalt
B. Iron
C. Ebonite
D. Steel
5. The direction of a magnetic field within a magnet is
A. from north to south
B. from south to north
C. back to front
D. front to back
6. The ability of a material to remain magnetized after removal of the magnetizing force is known as
A. hysteresis
B. retentivity
C. permeability
D. reluctance
7. When the current through the coil of an electromagnet reverses, the
A. direction of the magnetic field remains unchanged
B. direction of the magnetic field reverses
C. magnetic field expands
D. magnetic field collapses
8. When a magnet is suspended freely it always aligns itself in which direction?
A. North
B. N-S
C. N-W
D. N-E
9. Which type of magnet is used in cranes to lift heavy containers from ships?
A. Bar magnet
B. Cylindrical magnet
C. Electromagnet
D. Horseshoe magnet
10. Electric bell is an example of which magnet?
A. Bar magnet
B. Cylindrical magnet
C. Electromagnet
D. Horseshoe magnet
Answers will be updated soon..
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