问题 填空题

如图所示的电路中,电池的电动势为E,内阻为r,电路中的电阻R1、R2和R3的阻值都相同,在电键S处于闭合状态下,若将电键S1由位置1切换到位置2,则电压表示数将______,电池内部的功率将______(以上空格均选填“变大”、“不变”或“变小”).

答案

1.将电键S1由位置1切换到位置2,外电阻变小,电动势和内阻不变,电路中的总电流变大,内电压变大,外电压变小,电压表测的是外电压,所以电压表示数变小.

2、电路中的总电流变大,根据P=I2r,知,电源内部消耗的功率变大.

故答案为:变小;变大.

单项选择题 A型题
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Princeton University

Location

The University is in Princeton, New Jersey. It is an hour's train ride south of New York City and an hour's train ride north of Philadelphia.

Students

There are 4,600 undergraduates (本科生). There are also 1,900 post-graduate students, but Princeton is unusual among universities in having a student body made up largely of undergraduates.

Faculty

Princeton has about 700 full-time faculty members (教员). There are another 300 or so part -time and visiting faculty. All faculty members at Princeton are expected to teach and research.

Degrees

Princeton offers two undergraduate degrees: the bachelor of arts (A.B.) degree and the bachelor of science in engineering (B.S.E.) degree.

Academic Year

An academic year runs from September to late May and lasts two terms (fall and spring). A normal course load is four or five courses per term, although many students take extra courses.

Residences

Princeton provides housing for all undergraduate students. Freshmen and second-year students are required to spend their first two years in one of five colleges. Each college has its own dining hall, common rooms and computer centers.

Fees and Expenses (Academic Year 2004-2005)

Tuition (学费): $29,910

Room and board: $ 8,387

Other expenses (books, telephone, etc.): $ 3,083

Total: $ 41,380

小题1: How many kinds of faculty members are there in Princeton University?

A.Four.

B.Three.

C.Two.

D.One小题2: In Princeton University, an undergraduate will pay at least ________ for the Academic

Year 2004-2005 besides tuition.

A.$11,470

B.$ 52,850

C.$ 41,380

D.$ 8, 387小题3:In what way is Princeton University different from other American universities       according to the text?

A.All the faculty members at Princeton are expected to teach and research.

B.It provides housing for all undergraduate students.

C.Its students are mainly undergraduates.

D.It has five colleges.小题4: Which of the following is NOT true?

A.It's about an hour's train ride from Princeton University to the north of New York City.

B.Undergraduates should spend their first two years in one of five colleges.

C.An academic year lasts about nine months in Princeton University.

D.Princeton offers two undergraduate degrees.