There are exercises for the use of physical multi meter to ask for explanations.

When the ammeter is fully biased, that is, when the external circuit is shorted, ig=300 A R=e ig=

That is, the internal resistance of the ohmic file of the multi-meter is 5,000 ohms, when the resistance of the external circuit and the internal resistance are equal, the pointer of the ohmmeter points to the ** of the dial, so this resistance is called the median resistance of the ohm meter, when the resistance of the external circuit is near the median resistance, the pointer and the dial of the pointer are nearby, the error is smaller, and the measurement results are more accurate, so choose B

Analysis: The ohm scale is uneven, dense on the left and sparse on the right. Because the ** part of the scale is relatively uniform, the reading around the median resistance is the most accurate, so this question should first find the median resistance of the ohmmeter, and then choose according to the answer.

The median resistance of the ohmmeter is the internal resistance of the zeroed ohmic meter. Therefore, when the red pen and the black pen are directly connected to zero, ig=e (r0+r+rg), and r0+rg+r=e ig=5 kWhen the measured resistance rx=5 K, the ohmmeter pointer points in the middle, so the corresponding resistance is called the median resistance.

This shows that the range of resistance that can be accurately measured by this gear should be the range given by option b.

Answer: B

It is choice AWhat was said upstairs was right.

The explanation is as follows: when the red and black meter pen is shorted, the full bias current is 3mA, and the internal resistance R0 of the ohmmeter should be found first (it includes the internal resistance of the ammeter, the zeroing resistance and the internal resistance of the battery). So r0=e (3*10 -3).

Because when measuring 500 ohms, the dial is positive**, so ro+500=e (two consecutive columns can obtain r0=500 ohms.)

When the pointer is 1mA, r0+rx=e (1*10 -3) and then find a random formula from above to get rx=1000 ohms.

On this day, electricity w=1500r (3000r

The energy meter is increased on the basis of the previous day.

On this day, his family had to pay a bill for electricity.

On this day, electricity w=1500r (3000r

The number of electrical energy is expressed as.

On this day, his family had to pay a bill for electricity.

When the selector switch is placed at point C, it can be used to measure the voltage, when the voltage at both ends of a certain battery is measured, the red meter pen should be connected to the positive pole of the battery, and the current flows from the red meter pen into the multi-power meter, and the dial scale of the voltmeter is uniform (optional uniform, uneven);

When the selector switch is placed at point A, it can be used to measure the current, and after the circuit is connected, the current flows from the red meter pen into the multimeter;

When the selector switch is placed at point B, it can be used to measure the resistance, and the two watch pens should be shorted first, and the zero knob should be adjusted to make the pointer point to the dial The indication of resistance is 0, and the current flows out of the red watch pen at this time

(1) all give points); 173v (171 175v are all scored).

3) 67 (65 and 69 are all scored).

A 100W bulb uses a minute of electricity that:

One minute 360*1 600 = circle.

5-10A, 3-5A indicates the total current limit, choose according to your need.

Bulb, then working for 10 hours is 1kwh, so one minute turns 360 (60*10) = circles, you can count five minutes to turn 3 times, the meter with 5-10A and 3 5 A is different, 5-10A is the basic current when using 5A, the maximum current is 10A, 3 5A is the basic current is 3A, the maximum current is 5A, when connecting the ultra-high power load, calculate the current, it is best not to exceed the maximum current.

Number of laps in one minute = 360 * laps.

The main difference is the maximum test current of the meter.

(360*100) (1000*60)=turns.

The following 1000*60 is the conversion of units.

The current of the meter does not matter if you calculate the power.

The size of the meter generally depends on the power of your own household appliances, if the allowable current of the meter is too small, the fuse will often be blown out. Usually 5-10a, now.

Electricity consumed in one minute:

Revolutions: 360*1 600=

5-10A and 3-5A, is the amount of current that the meter is allowed to pass through or can withstand, that is, the range of the telegraph. Just like the amount of water that a river can pass, a small river will flow out of the river when it passes through a large water. If you use a meter with a small range of 3 5 amps, and if you measure 7 amps, the meter will burn out!

Therefore, it is necessary to choose the appropriate range when measuring, and measuring a small current with a large range will lead to a large error. Measuring large currents with a small range will burn the meter.

∵∴360r/

100W bulb, one minute revolution.

So it's turning.

It's simple

The multimeter has resistance, and if it is connected in parallel with the switch k, the luck is that the current will not pass through the multimeter.

Because it is a current meter, you can directly think of the multi-electric meter as an ammeter.

You don't rent a wire in parallel when you use an ammeter, do you?

To measure the current, the meter must be connected in series into the circuit, k is disconnected, and the current flows through the meter to achieve the purpose of measuring the current.

3. Use the ohmic block (r 1k) of the multimeter to check the crystal diode with good performance, and find that the angle of the meter hand deflection to the right is very small, which shows that (

a.The diode is equipped with a forward voltage prediction, so the measured resistance is very small bThe diode is redirected by a counter-ruler, so the measured resistance is very large. ac

psve r

rlc.At this point, the red pen is connected to the positive pole d. of the diodeAt this time, the red pen is connected to the negative pole of the diode.

w=100r÷2000r/kwh=

t=3min=

p=w/t=

10A is the maximum current that Yunbichun Xu Wildcard Hui dissipates when Peizhi is working normally, and 20A is the fusing current of the electric energy meter.