"Measurement of Current" Current and Circuit PPT Courseware 4

Description

"Measurement of Current" Current and Circuit PPT Courseware 4

learning target

1. Understand the magnitude of electric current, and know the unit and symbol of electric current.

2. Know the purpose of the ammeter and the correct usage rules, understand the range and graduation value of the ammeter, and read it correctly.

The flow of water can be strong or weak, but the current is invisible and intangible. So how do we know the strength of the current in the circuit?

Demonstration experiment:

The effect of the number of battery cells on the brightness of the light bulb

Phenomenon: The more batteries, the brighter the light

Note: Electric current also has strong and weak points.

When electric current passes through a conductor, it will produce various effects (including thermal effects, magnetic effects, chemical effects, etc.). We can judge the strength of the current based on the size of the effects produced.

1. How to express the strength of current

Current: (I) A physical quantity that represents the strength of an electric current.

Unit: ampere (A), milliampere (mA), microampere (uA)

Conversion: 1mA=10-3A 1uA=10-6A

2. Construction and reading of ammeter

Connection: one red and one black

Black "-" terminal

Red "+" terminal

3. How to read on the ammeter

①Clear the measuring range

Connected to 0.6 terminal: press the scale to read

Connect 3 terminals: Press the upper scale to read

②Determine the graduation value

Each small grid of 0.6 is 0.02A

Each small grid of even 3 is 0.1A

③Look at the watch hands pointing to the right

How many cells have been missed in total?

Thinking: Is there any error in the connection method of the ammeter below?

Phenomenon: The pointer of the ammeter is reversed.

Reason: The wires and the positive and negative terminals of the ammeter are connected reversely.

Solution: Replace the ends of the two wires connected to the ammeter.

Detection:

1. In Xiao Ming's experiment of measuring current with an ammeter, the recorded measurement result was 2.1A. Xiao Feng found that his measurement result was measured in the 0.6A range, but the reading was in the 3A range, so Xiao Ming's actual measurement The value should be ( ).

A. 2.1A B. 0.42A C. 2.12A D. 0.6A

2. Connect the physical diagram below so that the small bulb can emit light and the ammeter can measure the flowing current (estimated to be 0.1~0.3A).

4. Practice

1. Current is a physical quantity represented by ( ), usually represented by the letter ( ), its unit is ( ), abbreviated as ( ), and its symbol is ( ).

2. 7.5A=( )mA 5mA=( )A

50mA=( )μA 20000 μA=( )mA

6.2A=( ) μA 100 μA=( )A

3. The current in the circuit can be measured with ( ). When used, the current must flow in from ( ) and out from ( ). If the direction of the current in the meter is opposite, the needle of the meter will deflect to the ( ) side, so that not only ( ) but sometimes ( )

4. The ammeter must be connected to the electrical appliance under test ( ). When wiring, pay attention to choosing the appropriate one ( ). Under no circumstances can the ammeter be directly connected to ( ).

Expand and improve:

Use bulbs L1 and L2, a battery, and a switch S to form a circuit. It requires bulbs L1 and L2 to work at the same time. How many possible connection methods are there? Draw the corresponding circuit diagram. If you are asked to use an ammeter to measure bulb L1 and bulb L2 respectively and their total current, where should you place the ammeter? They are marked with A, B, and C in the figure respectively.

Keywords: Current and circuit teaching courseware, current measurement teaching courseware, New People's Education Edition ninth grade physics PPT courseware, ninth grade physics slide courseware download, current and circuit PPT courseware download, current measurement PPT courseware download, .ppt format

For more information about the "Measurement of Current, Current and Circuits" PPT courseware, please click on the "Measurement of Current ppt Current and Circuits ppt" tag.

"Measurement of Electric Current" PPT courseware:

The first part of the "Measurement of Electric Current" PPT courseware content: The strength of electric current 1. Current: a physical quantity indicating the strength of electric current, symbol I 2. Unit: Ampere, symbol A. There are also milliamps (mA) and microamps (A) 3 , Current unit conversion relationship: 1A＝1000mA 1mA＝100..

"Measurement of Current" PPT:

"Measurement of Electric Current" PPT Part One Content: Teaching Objectives 1. Understand the basic concepts of electric current. 2. Know the current values ​​of some household appliances. 3. Practice and master the current measurement methods and procedures. 4. Able to read ammeter according to standard methods. 5. Can press the button...

"Measurement of Current" Current and Circuit PPT Courseware 9:

"Measurement of Current" Current and Circuit PPT Courseware 9 Current 1. Current intensity: Indicates the size of the current. Current intensity is referred to as the current symbol I 2. The basic unit of current: ampere, referred to as ampere, symbol A. Common units: milliamps (mA) and Microampere (A) conversion relationship: 1A=..

File Info

Update Time: 2024-07-06

This template belongs to Physics courseware People's Education Edition Ninth Grade Physics Complete Book industry PPT template

Preview