The knowledge of junior high school electricity, the basic knowledge of junior high school electrici

The short circuit of the circuit is equivalent to connecting a wire in parallel, and the electrical appliances that occur short circuit can also be regarded as a wire. The voltmeter of the appliance connected in parallel in a short circuit will have no indication number, the power supply will burn out, etc. If the voltmeter is connected in series in the circuit, it is equivalent to an open circuit there, and the circuit is not closed, so there is no current.

A short circuit may occur because the ammeter is connected in parallel with the appliance, the switch is connected in parallel with the appliance, the appliance itself is short-circuited, and so on.

After something is short-circuited, there is voltage and current in the circuit, but there is almost no resistance. Because something is short-circuited, it is equivalent to a wire, and the resistance of the wire is negligible, so there is no indication on the voltmeter, and because the resistance is almost zero, there is a large indication on the ammeter.

If the sliding rheostat is connected in series with another electrical appliance, the series connection will divide the voltage, that is to say, when the resistance value of the sliding rheostat is equal to the resistance value of the electrical appliance, the two will share half of the total voltage, if the resistance value of the sliding resistor is greater than the resistance value of the electrical appliance, then the natural sliding rheostat will divide a little more voltage, when the resistance of the sliding rheostat becomes larger, the voltage it gets will become larger, and the resistance of the electrical appliance does not change, the series resistance is equal to the sum of the resistance of each electrical appliance, so the total resistance increases, the power supply voltage remains the same, so the total current will become smaller.

The rated voltage of the sliding rheostat refers to the maximum voltage it can distribute, and the rated current refers to the total current in the circuit where the sliding rheostat is located cannot exceed the rated current, if it does, the sliding rheostat may burn out.

What time are you in the middle of nowhere? Because the resistance of the voltmeter is too large, it will cause a small current to be connected directly to the circuit. It's equivalent to being disconnected there, so it's a broken circuit. Broken circuit.

Moreover, the sliding rheostat is connected in series and parallel in the circuit, the change of resistance will not affect the total voltage, only the change of the total voltage of the power supply voltage will change, in parallel, the voltage at both ends of the sliding rheostat does not change with the change of resistance, but the magnitude of the current is inversely proportional to the resistance.

1. The law of current in circuit and current, series circuit and parallel circuit;

2. Voltage and resistance, the law of voltage in series circuit and parallel circuit, and the factors affecting the size of resistance;

3. The relationship between current and voltage and resistance in the circuit ---Ohm's law, the total resistance of series circuit and parallel circuit;

4. Electrical energy and electrical work, thermal effect of electric current, electric power.

Words of Electricity Fill in the blanks: Ohm's Law Electrical Power Circuit Fault Analysis Diagram Questions: Magnetic Poles Right Hand Rule.

Experiment Question: Small Bulb Resistance Small Bulb Electric Power.

Calculation Questions: Ohm's Law, Electric Power, Joule's Law.

Application of Ohm's law, electrical power.

The series and parallel connection of resistors, some Ohm's laws, the resistance of circuits and the change of voltage and current...

There is also an energized coil, and the bias of the small magnetic needle on the side of the energized wire, with the right-hand spiral rule...

1.Ohm's Law 2Characteristics of series-parallel circuits 3Acquisition and conversion of electrical energy 4Electric work, electric power.

Ohm's law, string, parallel, Joule's law.