Electric Circuit

Solution

Problem

V=1V Suppose that resistance equals one volt
1=1 amp and current equals one ampere.
R=? How much is the resistance?

2. Solve the following problems and read them.

Model: - How much is 10 times 4? - 10 times 4 equals 40.

5)350 x 2 = 6)3.5x10 = 7) 2,000 x 5 = 8)0.12x2 =

9) 49: 7 = 10) 75: 25 = 11)3,500:35 12)10.25:10

1)7x7 = 2)2.5x3 = 3)10,050x2 = 4)100x0.5 =

IV

I

= lohm

lamp

13) 20.25 x 30^:

14) 7.5: 5 = 15)40.8:4 = 16) 15.5: 3=

circuit l's3:kit]

conductor [кэпУлМэ]

function ['fAnkJn]

difference ['difrans]
open
short

trouble [ЧглЫ]

no [nou]

to reduce [n'dju:s]

to supply jsa'plai]

to connect [ka'nekt]
to compare (with) [кэт'рбэ]

to pass through ['pa:s 'Gru:]
to result in
to result from

цепь, контур

проводник

назначение

разница

обрыв

короткое замыкание

повреждение

никакой, нисколько

сокращать

снабжать

связывать

сравнивать (с)

проходить через

приводить к, иметь результатом

следовать, проистекать из

-8-

-9-

3. What does an open in a circuit result in? 4. What does a short in a circuit result in? 5. What does a trouble in a circuit result from?

This is a circuit. Its elements are a voltage source, a resistor and a conductor. The circuit consists of a voltage source, a resistor and a conductor. A voltage source supplies current. A resistor reduces current. A conductor connects the elements of the circuit.

Compare circuit a with circuit b. What is the difference between them? Current passes through circuit a while no current passes through circuit b. Circuit b has an open. No cur­rent through circuit b results from an open. An open and a short are troubles in a circuit. A trouble in a circuit may result in no current in it.

3. Complete these sentences, using the correct variant:

1. Circuit a consists of a) resistors and conductors.

b) a voltage source and resistors.

c) a voltage source, a resistor and a conductor.

4. Answer the following questions:

1. What elements does a circuit consist of?

2. What is the function of a voltage source?

3. What is the function of a conductor?

4. What is the function of a resistor?

5. When is there no current in a circuit?

6. What does an open or a short result in?

7. What does no current in a circuit result from?

5. Solve these problems:

1. How much is the current in the circuit if a 60-volt source is connected to a resistance of 1,600 ohms?

2. How much is the voltage in a circuit having a current equal to 25 amp, if a 25-ohm resistance is connected to it?

3. A 70.35-ohm resistance is connected to the circuit. How much is the voltage if the current equals 4.5 amp?

6. Pair work. Ask your groupmate to compare circuits a and b (see Fig. 1).

1. What do they have in common?

2. Which of the circuits has a trouble?

3. What does the trouble result from?

4. What does it result in?

2. A voltage source

a) conducts current.

b) reduces current.

c) supplies current.

3. A conductor

a) connects the elements.

b) supplies voltage.

c) conducts current.

4. A resistor

a) connects the elements.

b) supplies current.

c) reduces current.

5. No current results from a) an open.

b) a short.

Дата добавления: 2015-05-08