Electricity and Magnetic Fundamentals

21. A magnetic pole produces 5000 field lines. How much is the flux in webers?

1. 5O X 10∧-6
2. 5 X 10∧-6
3. 500 X 10∧-6
4. 500 X 10∧-5

View answer

22. A magnetizing force of 1000 AT/m will produce a flux density of _________ in air.

1. 1.257 mWb/mA2
2. 0.63 Wb/m∧2
3. 1.257 Wb/m∧2
4. 0.63 mWb/m∧2

View answer

23. A negative ion results when an atom gains an additional

1. Electron
2. Proton
3. Neutron
4. Atom

View answer

24. A negatively charge body has

1. deficit of electrons
2. excess of protons
3. excess of electrons
4. deficit of neutrons

View answer

25. A one cubic cm of copper has how many free electrons at room temperature?

1. 80 X 10∧18
2. 8.5 X 10∧22
3. 20 X 10∧10
4. 50 X 10∧20

View answer

26. A permanent magnet does not exert a force on

1. an unmagnetized iron bar
2. a magnetized iron bar
3. a moving electric charge
4. a stationary electric charge

View answer

27. A positively charged body has

1. deficit of electrons
2. excess of neutrons
3. excess of electrons
4. deficit of protons

View answer

28. A principle that states that only two electrons with different spins are allowed to exist in a given orbit

1. Bohr's principle
2. Pauli exclusion principle
3. Avogadro's principle
4. Coulomb's principle

View answer

29. A substance that attracts pieces iron

1. Conductor
2. Semiconductor
3. Magnet
4. All of the above

View answer

30. A t/m is a unit of

1. Mmf
2. Emf
3. Reluctance
4. Magnetizing force

View answer