"Series and Parallel Connections of Resistors" Ohm's Law PPT Courseware 2

Description

"Series and Parallel Connections of Resistors" Ohm's Law PPT Courseware 2

Review questions:

1. Do you know the verbal expression and alphabetical expression of Ohm's law?

(1) Language expression:

The current in a conductor is directly proportional to the voltage across the conductor and inversely proportional to the resistance of the conductor.

(2) Letter expression: I=U/R

2. Do you still remember the laws of current and voltage in series and parallel circuits?

Current (I) characteristics

The current is equal everywhere in a series circuit. That is: I=I1=I2

In a parallel circuit, the trunk current is equal to the sum of the branch currents. That is: I=I1+I2

Voltage (U) characteristics

The total voltage across a series circuit and the sum of the voltages of each part of the circuit. That is: U=U1+U2

In a parallel circuit, the voltages at both ends of each branch are equal. That is: U=U1=U2

learning target:

1. Ability to derive the relationship between resistances in series and parallel circuits based on Ohm's law and circuit characteristics.

2. Use Ohm's law to derive the quantitative relationship between series resistance and parallel resistance.

3. Use Ohm's law to derive the laws of series voltage division and parallel division.

1. The relationship between the total resistance and the partial resistance of the series circuit:

It follows that the total resistance of a series circuit is equal to the sum of its partial resistances. That is: R total = R1 + R2

Supplementary explanation: (1) The total resistance of the series circuit is greater than any one partial resistance, because the series connection is equivalent to increasing the length of the conductor.

(2) The total resistance of n identical resistors connected in series is nR.

2. The relationship between the total resistance and the partial resistance of the parallel circuit:

It follows that the reciprocal of the total resistance of a parallel circuit is equal to the sum of the reciprocals of the partial resistances.

Supplementary explanation: (1) The total resistance of the parallel circuit is smaller than any one partial resistance, because the parallel connection is equivalent to increasing the cross-sectional area of ​​the conductor.

(2) The total resistance of n identical resistors connected in parallel is

Operation:

1. You are given three fixed-value resistors, each of which is 10Ω. Please connect them to the circuit in different ways, draw the circuit diagram, and calculate the corresponding total resistance value? (write down the calculation process)

2. There is a soldering iron with a resistance of 440Ω and a voltage of 220V during normal operation. Now connect it to a 380V power supply. In order to work normally, what size resistor should be connected to it? What is the current during normal operation?

3. As shown in the figure, the power supply voltage remains unchanged, R1=7Ω, R2=8Ω, and the voltage indicates 4V after closing the switch. What is the power supply voltage? (solve using two methods)

4. As shown in the figure, when the switch is closed, the indications of A1 and A2 are 0.4A and 1A respectively, and R2=4Ω. Find: the resistance of R1 and the power supply voltage.

Keywords: Ohm's law teaching courseware, series and parallel connection of resistors teaching courseware, Lujiao version ninth grade physics PPT courseware download, ninth grade physics slide courseware download, Ohm's law PPT courseware download, resistor series and parallel PPT courseware download, .PPT format;

For more information about the "Ohm's Law Series and Parallel Connection of Resistors" PPT courseware, please click the Ohm's Law ppt Series and Parallel Connection of Resistors ppt tag.

"Series and Parallel Connections of Resistors" Ohm's Law PPT courseware:

"Series and Parallel Connections of Resistors" Ohm's Law PPT courseware Review questions: 1. What are the laws of current and voltage in series and parallel circuits? Characteristics of current (I) Series circuit The current is equal everywhere in a series circuit. That is: I=I1=I2 Parallel circuit In a parallel circuit...

File Info

Update Time: 2024-07-07

This template belongs to Physics courseware Lu Jiao Edition Ninth Grade Physics Volume 1 industry PPT template

Preview