"Measuring Voltage" Understanding Circuits PPT Courseware 4

Description

"Measuring Voltage" Understanding Circuits PPT Courseware 4

Voltage is what causes current to form

Why does the small light bulb light up when the switch is turned on (click the switch)?

How is electric current formed?

Voltage is what causes current to form

Animation demonstration, please click "Think" and "Open the valve" to try

1. Water flow:

The height difference of water (water level difference, water pressure difference) - the role of water pressure: the cause of water flow.

2. Current:

Charge (positive charge, negative charge)

Electrical height difference (potential difference, voltage difference) - the role of voltage: the cause of current flow.

1. Voltage

1. The meaning of voltage

Voltage is the cause of current (the symbol of voltage is represented by U.)

2. Unit of voltage:

International unit: volt (volt), referred to as volt (V).

Commonly used units: kilovolts (kV); millivolts (mV).

Conversion: 1 kV =1 000 V= 103 V

1 mV=0.001 V= 10-3 V

3. Several commonly used voltages

The voltage of a dry cell U=1.5 volts

The voltage of a lead-acid battery U = 2 volts

Household circuit voltage U = 220 volts

Industrial power voltage U=380 volts

The voltage that is safe for the human body is not higher than 36 volts

2. Measurement of voltage

1. Voltmeter

Read the instructions:

Purpose

(1) A voltmeter is an instrument for measuring low-value DC voltage;

(2) Connection of commonly used voltmeters;

(3) Usually two measuring ranges are used: (0~3 V) and (0~15 V).

Structure

See the figure for the appearance. The pointer is set to zero at the left end of the scale. There are two scales on the scale, which are 0~3 V and 0~15 V. The zero adjuster is directly below the reading window. The terminals are marked with "—", "3", and "15" respectively, among which the "—" terminal is the common terminal.

2. Use of voltmeter:

(1) The voltmeter should be connected in parallel in the circuit

(2) The "+" and "-" terminals must be connected correctly

(3) The measured voltage should not exceed the range of the voltmeter

3. Practice measuring voltage with a voltmeter

experiment

(1) How to connect the voltmeter?

(2) Reading of voltmeter

Reading steps:

The first step is to look at the measuring range;

The second step is to look at the minimum graduation value;

The third step is reading.

(3) Manually measure the voltage across the electrical appliance and the voltage across the power supply.

practice

1. Which of the following statements is correct ( )

A. If there is voltage at both ends of the circuit, there must be continuous current in the circuit.

B. There are a large number of free charges in the conductor. As long as a path is formed, there will be current in the conductor.

C. Voltage is the cause of current in a circuit

D. If there is current in the circuit, there is not necessarily voltage.

2. Regarding the use of voltmeter, the correct one is ( )

A. The voltmeter cannot directly measure the power supply voltage, otherwise it will burn out.

B. Choose as large a range as possible to avoid damaging the voltmeter.

C. After testing, if the measured voltage does not exceed the small range, the smaller range should be selected.

D. When the voltmeter is connected to the circuit, there is no need to consider the connection method of the "+" and "-" terminals.

3. As shown in the figure, to use the voltmeter to measure the voltage at both ends of the lamp L2, the correct circuit diagram is ( )

4. In the circuit shown in the figure, after the switch is closed, the consequences will be ( )

A. The ammeter and voltmeter were burned out

B. Neither the ammeter nor the voltmeter will be burned out.

C. Only the voltmeter will be burned out

D. Only the ammeter will be burned out

5. As shown in the picture, Xiaoqi uses a voltmeter to measure the voltage across the bulb L1. In order to continue to measure the voltage across the bulb L2, she disassembles the left terminal of the voltmeter and connects it to point C. Is this correct? Why?

Keywords: Understanding circuit teaching courseware, Measuring voltage teaching courseware, Shanghai Science Edition ninth grade complete physics PPT courseware download, Ninth grade physics slide courseware download, Understanding circuit PPT courseware download, Measuring voltage PPT courseware download, .PPT format;

For more information about the PPT courseware "Understanding Circuits and Measuring Voltage", please click the "Understanding Circuits and Measuring Voltage ppt" tag.

"How to Understand and Measure Voltage" Exploring Simple Circuit PPT Courseware 2:

"How to Recognize and Measure Voltage" Exploring Simple Circuit PPT Courseware 2 Voltage is the cause of the formation of current. Why does the small light bulb light up when the switch is closed (click the switch)? How is electric current formed? 1. Water flow: water height difference (water level difference, water pressure difference) water pressure...

"How to Understand and Measure Voltage" explores simple circuit PPT courseware:

"How to Recognize and Measure Voltage" Exploring Simple Circuit PPT Courseware Learning Objectives 1. Know what voltage is, know that a power supply is a device that provides voltage, and know the units of voltage: volts, kilovolts, and millivolts. 2. Know common power supplies and some voltage values. 3. Will be used..

"Measuring Voltage" Understanding Circuit PPT Courseware 5:

"Measuring Voltage" Understanding Circuits PPT Courseware 5 A colored light bulb requires a voltage of 22V when it glows normally. They are connected to a 220V household circuit. How should they be connected to make the circuit work safely? In a series circuit, the total voltage across the circuit is the same as the voltage across each part of the circuit..

File Info

Update Time: 2024-09-30

This template belongs to Physics courseware Shanghai Science Edition Ninth Grade Physics industry PPT template

Preview