"Rheostats" PPT download

Description

"Rheostats" PPT download

Part One: Knowledge Review

1. What physical quantity is resistance?

Answer: Resistance is a physical quantity that represents the resistance of a conductor to current; the greater the resistance, the greater the resistance to current.

2. What are the factors that affect the size of the resistor?

Which factor is most convenient to use to change the size of the resistor?

Answer: Factors that affect resistance include material, length, cross-sectional area, and temperature.

It is easiest to change the resistance value by changing the length.

Rheostat PPT, Part 2: Discussion

Which of the following connections are correct? What are the characteristics

1. One end of the terminal is connected to the metal rod (top), and the other end is connected to the terminal of the resistance wire (bottom).

Applications of sliding rheostat

Ask a question:

How to use a rheostat to change the brightness of a light bulb?

Conjectures and Assumptions:

Conjecture 1: When a rheostat is connected in parallel with a light bulb, the brightness of the light can be changed.

Conjecture 2: When the rheostat is connected in series with the light bulb, the brightness of the light can be changed.

design experiment:

1) Connect the circuit according to the circuit diagrams 1 and 2 below respectively. Before closing the switch, be careful to move the slider of the sliding rheostat to the position of maximum resistance.

2) Close the switch, move the slider, and observe whether the brightness of the bulb changes?

Rheostat PPT, Part 3: Precautions for using sliding rheostat:

1. Wiring: One end is connected to the terminal of the metal rod, and the other end is connected to the terminal of the resistance wire. (one up and one down)

2. Connect the circuit to the maximum value before closing the switch. (protect the circuit)

3. Series connection in a circuit can change the current in the circuit.

Rheostat PPT, Part 4: Classroom Exercises

1. The following varistor terminals are connected correctly ( )

2. When the varistor slide moves toward end A, the R value becomes larger, and the connection is correct ( )

3. The nameplate of a certain sliding rheostat is marked with "100Ω2A", which means

meaning is______________________________.

As shown in the figure below, if AB of the sliding varistor is connected to the circuit,

When the slider P is at the far left end, the resistance connected to the circuit is ___ Ω;

When the slider P is at the midpoint, the resistance of the connected circuit is ____ Ω;

When the slider P is at the far right end, the resistance of the connected circuit is ___ Ω.

Keywords: Zhejiang Education Edition eighth grade science PPT courseware free download, rheostat PPT download, .PPT format;

For more information about the "Rheistor" PPT courseware, please click the "Rheistor ppt" tab.

"Rheostats" PPT courseware:

"Rheistor" PPT courseware part one content: Rheostat 1. Rheostat: Principle of a device used to change the resistance: the size of the resistance changes with the length of the conductor. The maximum resistance value of this sliding varistor is 20, and the maximum current allowed is 2A. ..

"Rheostats" PPT:

"Rheistor" PPT Part One Content: Review Resistance (symbol: R) 1. Concept: The obstruction effect of conductors on current flow. The more resistant a conductor is to the flow of electricity, the greater its resistance. 2. Unit: ohm (ohm) (symbol: ) kiloohm (K), megaohm..

"Rheostats" Voltage and Resistance PPT Courseware 2:

"Rheostats" Voltage and Resistance PPT Courseware 2 1. Resistance of the Conductor 1. Resistance: Indicates the resistance of the conductor to the current. 2. The greater the resistance of the conductor, the greater the resistance to the current. 3. The symbol of resistance in the circuit diagram 4. The unit of resistance: ohm symbol 5..

File Info

Update Time: 2024-11-01

This template belongs to science courseware Zhejiang Education Edition Eighth Grade Science Volume 1 industry PPT template

Preview