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3 years ago

Please help me out i'm so depressed and such a failure

Physics

1 answer:

Anika [276]3 years ago

5 0

Answer: a variety of ohmic valu example, VIN = VR1 + VR2.

Potentiometer Example No1

A resistor of 250 ohms is connected in series with a second resistor of 750 ohms so that the 250 ohm resistor is connected to a supply of 12 volts and the 750 ohm resistor is connected to ground (0v). Calculate the total series resistance, the current flowing through the series circuit and the voltage drop across the 750 ohm resistor.

potentiometer example one

Explanation:

uman ear has a logarithmic response and is therefore non-linear.

If we where to use a linear potentiometer to control the volume, it would give the impression to the ear that most of the volume adjustment was restricted to one end of the pots track. The logarithmic potentiometer however, gives the impression of a more even and balanced volume adjustment across the full rotation of the volume control.

So the operation of a logarithmic potentiometers when adjusted is to produce an output signal which closely matches the nonlinear sensitivity of the human ear making the volume level sound as though it is increasing linearly. However, some cheaper logarithmic potentiometers are more exponential in resistance changes rather than logarithmic but are still called logarithmic because their resistive response is linear on a log scale. As well as logarithmic potentiometers, there are also anti-logarithmic potentiometers in which their resistance quickly increases initially but then levels off.

The all potentiometers and rheostats are available in a choice of different resistive tracks or patterns, known as laws, being either linear, logarithmic, or anti-logarithmic. These terms are more commonly abbreviated to lin, log, and anti-log, respectively.

The best way to determine the type, or law of a particular potentiometer is to set the pots shaft to the center of its travel, that is about half way, and then measure the resistance across each half from wiper to end terminal. If each half has more or less equal resistance, then it’s a Linear Potentiometer. If the resistance appears to be split at about 90% one way and 10% the other then chances are it’s a Logarithmic Potentiometer.

Potentiometer Summary

In this tutorial about potentiometers, we have seen that a potentiometer or variable resistor basically consists of a resistive track with a connection at either end and a third terminal called the wiper with the position of the wiper dividing the resistive track. The position of the wiper on the track is adjusted mechanically by rotating a shaft or by using a screwdriver.

Variable resistors can be categorised into one of two operational modes – the variable voltage divider or the variable current rheostat. The potentiometer is a three terminal device used for voltage control, while the rheostat is a two terminal device used for current control.

We can summarise this in the following table:

Type Potentiometer Rheostat

Number of

Connections Three Terminals Two Terminals

Number of Turns Single and Multi-turn Single-turn Only

Connection Type Connected Parallel with a Voltage Source Connected in Series with the Load

Quantity Controlled Controls Voltage Controls Current

Type of Taper Law Linear and Logarithmic Linear Only

Then the potentiometer, trimmer and rheostat are electromechanical devices designed so that their resistance values can be easily changed. They can be designed as single-turn pots, presets, slider pots, or as multi-turn trimmers. Wirewound rheostats are mainly used to control an electrical current. Potentiometers and rheostats are also available as multi-gang devices and can be classified as having either a linear taper or a logarithmic taper.

Either way, potentiometers can provide highly precise sensing and measurement for linear or rotary movement as their output voltage is proportional to the wipers position. The advantages of potentiometers include low cost, simple operation, lots of shapes, sizes and designs and can be used in a vast array of different applications.

However as mechanical devices, their disadvantages include eventual wear-out of the sliding contact wiper and/or track, limited current handling capabilities (unlike Rheostats), electrical power restrictions and rotational angles that are limited to less than 270 degrees for single turn pots

You might be interested in

At constant volume, the heat of combustion of a particular compound is − 3550.0 kJ / mol. When 1.075 g of this compound ( molar

swat32

Answer:

$C=1,25\cdot 10^{5} kJ/^{\circ}C$

Explanation:

First of all let's define the specific molar heat capacity.

$C = \frac{-Q}{n\cdot \Delta T}$ (1)

Where:

Q is the released heat by the system

n is the number of moles

ΔT is the difference of temperature of the system

Now, we can find n with the molar mass (M) the mass of the compound (m).

$n=\frac{m}{M}=6.95\cdot 10^{-3} moles$

Using (1) we have:

$C=\frac{-3550}{6.95\cdot 10^{-3} 4.073}$

$C=1,25\cdot 10^{5} kJ/^{\circ}C$

I hope it helps!

6 0

3 years ago

What are five examples that illustrate a machine or a person doing work on another?

valentina_108 [34]

I sort of understand but what does it mean by.... Another?

5 0

3 years ago

How many protons would the element with the atomic number 10 contain?

galben [10]

The atomic number is the same as the proton number so the answer would be D) 10

3 0

3 years ago

After a magnetic field is applied, how many energy levels would you expect for then=3,ℓ=2 state, including electron spin?

zloy xaker [14]

Answer:

The energy level is 5.

Explanation:

Given that,

n = 3

l = 2

We know that,

l shows the number of sub-shells and define the number of angular nodes.

n shows the number of electron shell.

$m_{l}$ is a quantum number. It is define the number of energy level in a sub-shells .

$m_{s}$ is define the spin of the electron.

So, The quantum number is

$m_{l}=-2,-1,0,1,2$

$m_{s}$ is $+\dfrac{1}{2}$ and $-\dfrac{1}{2}$ for every energy level.

The energy level is 5.

Hence, The energy level is 5.

7 0

3 years ago

Calculate the radiative and collisional energy losses (in keV/micron) for a 1.9 MeV electron in lead and determine the rad./coll

Andrew [12]

Answer:

Explanation:

During an energy transfer, the collision loss for an electron can be determined by using the formula:

$Q = \dfrac{4mME }{(m+M)^2}$

However; from the total stopping power & power loss of the electron;

$\dfrac{radiational \ energy \ loss}{colisional \ energy \ loss } = \dfrac{ZE}{800}$

where;

Z = atomic no. for lead = 82

E = 1.9 MeV

∴

radiational energy loss = collisional energy loss $=\dfrac{82 \times 1.9}{800}$

= 0.19475

Normally, the traditional lead shielding in its pure shape contains high brittleness. However, the functionality of this carbon group chemical element is useful for protection because it has an excessive density.

Initially, the conventional lead protection however reduces the mild clarity at the same moment as plexiglass is useful for light transmittance and readability.

Moreover, the traditional lead with its high density and thickness reduces observation features, in the meantime, the plexiglass is a whole lot higher than the stated.

Finally, plexiglass contains a high dimensional balance with an excessive dielectric constant.

4 0

3 years ago