Put the verbs in brackets into the correct present tense.
A: When (the party/start)?
B: It (start) at 10 o’clock, so we (meet) at 9:30 at the bus station.
A: Mike (look) bad. (he/have) any troubles?
B: Yes, and he (think) of taking a holiday.
A: (you ever be) to a music festival?
B: Actually, I (go) to the concert this week.
A: You look exhausted. What (you do)?
B: I (do) my homework since morning.
A: Why (you look) so happy?
B: I (just find) 10 dollars in the street.
Жизнь человека неразрывно связана с природой. В старину люди чувствовали себя частью окружающего мира. Постепенно это чувство заметно уменьшилось. «Царь природы» превратился в того Ваньку, который не помнит своего родства.
Теперь не нужно бегать с дубинкой за мамонтом, чтобы пообедать и одеться. Вода сама приходит в дом по трубам. В доме всегда светло и тепло, непогода остается за окном. На полях работают мощные тракторы, комбайны – не нужно ковырять землю палкой, чтобы вырастить несколько мешков зерна. Человек сумел приручить многие силы природы и создать мощные машины. Люди создали оружие, которое по их желанию может убить других людей в любой точке планеты.
1. The ohmmeter is used to measure the value of resistance while it is connected in paralltl to the resistor.
2. The ammeter is connected in series while the current is being measured.
3. While the value of current in the circuit is measured, the ammeter should be connected in series.
1. Suppose the ammeter scale reads 1.9 amp, the voltmeter scale reads 2.4 V; how much is the value of resistance in the measured circuit?
R = U / I = 2.4 / 1.9 = 1.26 Ohm
2. Suppose the ohmmeter scale reads 75 ohms, the voltmeter scale reads 220 V; how much is the value of current in the measured circuit?
I = U / R = 220 / 75 = 2.9 A
3. Suppose that you have a series circuit consisting of three resistors and a voltage source. R1 = 0.18 ohm, R2= 1.15 ohms, R3 = 2 ohms, I=10 amp. Find the voltage drop across each resistor; find the value of voltage in the circuit.
U1 = R1 * I = 0.18 * 10 = 1.8 V
U2 = R2 * I = 1.15 * 10 = 11.5 V
U3 = R3 * I = 2 * 10 = 20 V
Suppose R1 gets open. What does it result in? I = 0
4. Two resistors are connected in series. R1 = 7,000, R2= 2,200, I = 110 amp. Find the voltage drop across each resistor.
U1 = R1 * I = 7,000 * 110 = 770,000 V
U2 = R2 * I = 2,200 * 110 = 242,000 V
Suppose no current passes through the circuit, what does it result from?
It results from the broken circuit.