Определите суммарный заряд электронов, если их общая масса m=7,55⋅10−6 г. Масса одного электрона m0=9,11⋅10−31 кг
(ответ округли до целого значения)

R1 = 100 Ом         Решение:                              R(посл)=100+200 = 300 Ом  
R2 = 200 Ом         R(посл) = R1 + R2                P(посл) = 24²/300 = 1,92 Вт 
U = 24 B                  P(посл) = U²/R(посл)     R(пара)=1/100+1/200=0,015 Ом 
P(пара) - ?            R(пара) =1/R1+1/R2          P(пара)=24²/0,015=38400 Вт
P(посл) - ?            P(пара) = U²/R(пара)      n = 38400/1,92 = 20000
                              n = P(пара)/Р(посл)    ответ:Мощность при параллельном подключений 20000 раз больше чем при последовательном
подключений.

Exercise 1
1. They often make sandwiches for lunch.
2. I am not study at the moment.
3. I never study at night.
4. She talks to her friends every day.
5. She is not talking to her friends at the moment.
6. We have lessons every day.
7. We are not having an English lesson now.
8. He usually plays with Jim or Henry.
Exercise 2
1. The telephone rang while I was having a hot shower.
2. When you phoned last night, I was reading a fantastic book.
3. Mary and I saw Henry while we were waiting for the bus this morning.
4. Last night we were having dinner with friends when Helen arrived.
5. While the teacher explained the problem, Lisa was dropping her books.