2_kurs_4_semestr

31)A property that causes some particles to attract each other and others to repel each other. ___

32)A substance with many free electrons. ___

33)A device that uses conducting foil to detect charge. ___

34)The removal of static electricity by conduction to the earth. ___

35)A circuit that gives electrons more than one path along which to move. ___

36)A unit used to measure potential difference. ___

37)An instrument used to measure current. ___

38)A flow of electrons. ___

39)A unit used to measure resistance. ___

2. Select the letter of the answer that best completes each of the following:

40)What kind of charge do electrons have? a. positive

b. negative c. no charge

d. sometimes positive, sometimes negative

41)Electrons may be moved from one substance to another by …

a.using an insulator

b.heating

c.rubbing

d.all of the above.

42) Charges that can move between atoms are …

a.free electrons

b.free protons

c.free neutrons

d.all of the above.

43) Copper is a better conductor than glass. This is because …

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a.copper has more atoms

b.glass has more free electrons

c.copper has more free electrons

d.the electrons in copper are bound tightly to their atoms.

44) As two charges move closer to each other, the electric force between them

…

a.increases

b.decreases

c.stays the same

d.increases, then decreases.

45) Current is measured in …

a.volts

b.ohms

c.voltage

d.amperes.

46) A device that opens or closes a circuit is a …

a.load

b.source

c.switch

d.battery.

3. Complete the following:

47)Opposite charges ….

48)Electricity that is not moving is ….

49)A path along which electrons flow is a ….

50)The work needed to move a charge from one point to another is the ….

Points: 50

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IV. Conditional Sentences.

Choose the correct answer:

51) Plants die if you (not/water) them.

a.won‘t water

b.don‘t water

c.wouldn‘t water

52)If I had one million dollars, I (probably/buy) a yacht. a. would probably buy

b. will probably buy c. probably bought

53)‗How did it happen that you missed your stop?‘ ‗I (not/miss) it if the conductor (announce) the stops.‘

54) What a pity my husband is away! If he (be) here, he (help) us.

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57) If Benjamin Franklin (not/work) so hard, he (not/become) the symbol of America.

IV. Modal Verbs.

Choose the correct answer:

61) You will …speak Spanish in another few months.

a.can

b.have

c.be able to

d.ought

62) Nobody answers the phone. They …be out.

a.should

b.would

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c.can

d.must

63) I‘m sorry, I …have phoned to tell you I was coming.

a.should to

b.ought to

c.had to

d.could

64) To my mind, the government …take care of old people.

a.ought

b.need to

c.must

d.may

65) I …get up early on Mondays.

a.am able

b.have to

c.must

d.may

66) The policeman told the woman she …worry.

a.needn‘t

b.needn‘t to

c.couldn‘t

d.mustn‘t

67) …you mind passing me the salt?

a.will

b.should

c.could

d.would

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68) As you …remember, I was always interested in scientific experiments.

a.may

b.have to

c.must

d.ought to

69)Little children like books with large print. They …read them more easily. a. should

b. must c. can

d. have to

70)…I speak to Jane, please?

a.could

b.shall

c.must

d.ought

Points: 20

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97

98

99

100