Have a look a t the energy meter. A few technical specifications can be read. So you can see that the impulse constant output of this meter (电能表常数) is 1200 imp/(kW·h). What does "1200 imp/(kW·h)" stand for?

From the surface of the meter, we can get that the current rating (额定电流) of the meter is 5(60) A. The value in the bracelet——60 A——means that __________.

From the surface of the meter, we can get that the current rating (额定电流) of the meter is 5(60) A. The value out of the bracelet——5 A——means that __________.

If the impulse constant output of an energy meter is "3200 imp/(kW·h)", and the indicator light flashes 9600 times. How much energy is consumed?

2 kW·h = __________ J

1.08×10^6 kW·h = ________ J

If the impulse constant output is 2000 imp/(kW·h)， and 4 kW·h energy is consumed. How many times does the indicator light flashes?

If a circuit works under a power supply of 6V, and the current is 3A, during 10 seconds, how much electrical energy is consumed (or you can say: how much work has been done by the current)?

If the electrical work is 320J, and the voltage across and the current through are 1.6V and 0.2A, respectively. Please calculate the time. How many seconds?

If current does work of 2000 J during a period of 25 seconds, what is the electrical power?

If a light bulb works at a voltage of 3V and current through it is 0.15A, please calculate its electrical power.

What is the unit of electrical power?

What is the unit of electrical work?

What does electrical power measures?

If the total resistance is 5 ohms, and the main current is 6A, during a process of 20 seconds, how much is the electrical heating?

What does electrical heating (电热) measure?

Who came up with "Thermal effect of current", and also conclude with a formula "Q = I^2 ×R× t" to quantitatively calculate the amount of the thermal energy.

Joule's Law "Q = I^2 R * t" provides us a way to get the amount of the heat generated in the conductor. So what is the unit of Q?

We have learned the following three important formulas in this chapter:

1. W = U * I * t

2. Q = I^2 R * t

3. P = U * I

The question is：what are the respective exact meaning of W, Q, P

The illstruting diagram shows you the rated powers (额定功率) of some common electrical appliances. e.g. The rated power of an electrical kettle （电热水壶）is 1000W. So what is the definition of rated power?

What is the definition of rated voltage (额定电压)？

If 4800J electrical heating is generated in 2 minutes for a conductor, whose resistance is 10 Ω, then what is the current through the conductor?

It is common sense that in a household circuit the switch must be connected to _________ instead of the two other wires, for the sake of safety.

It is common sense that the potential difference between live wire and neutral wire is _____ V, and that between hot wire and earth wire is _____ V, and that between neutral wire and ground wire is _____ V.

What is single-line shock? A man who stands on the ground touches _______at the same time. Because in this way there is a voltage of 220V across him.

What is double-line shock? A unlucky man touches______________with two parts of his body at the same time. Because in this way his body experiences a voltage of 220V.

For home appliances such as refrigerators, air conditioners, etc, ground wire is so necessary. People connect the appliances to earth wire mainly in order to _________.

Observe the socket.

The upper pin should be connected to _______,

the left pin should be connected to _______,

and the right pin should be connected to _______,

We use an electrical tester to judge whether it is live wire. Make sure your hand is touching ________.

You mustn't touch _____ when you are working on the electric tester for it will put you into danger.

If the electric tester glows, it shows that the tester is connected with a(n) ________.

Both circuit breakers（断路器）and fuses (熔断器，保险丝) serves as an equipment that __________.

Who came up with "Thermal effect of current", and also conclude with a formula "Q = I^2 ×R× t" to quantitatively calculate the amount of the thermal energy.