Electrical voltage

Voltage is defined as electromotive force (emf) it is one of the Ohm's law parameters, it can be found in both Alternative Current (AC) and direct current (DC), it is measured in volt that can symbolize as V
Expression of emf =  FLq = qvBLq =vBL
Hence, emf =vBL
Voltage can also be defined as the measure of potential energy. Potential means an object that is in a stationary state, this means voltage is stationary unless charges force it to move. As the voltage increases, the current also increase. Let look at different stages or level of voltage for instant 330kv is higher than 133kv followed by 33kv then 11k and 415v. Some stages are for industries and big organization while some level of voltage is for domestic use.
Voltage refers to an electric potential difference, electric pressure or electric tension. It is the change in electric potential between two points. It has the dimension as ML2 T-3 1-1.
Voltage is nonlinear to current. It can be step up or step down.
A voltmeter can be used as the instrument used to measure the amount of voltage between two points in a circuit. As stated earlier, voltage is the measure of potential energy between two points. A question can come out like this is the tension of voltage between two points uniform or varied? Yes, it varies.
Let look at the following illustration.

Point A__________________________ Point C,
                                    Point B
observing above two points, the tension of  point B is high than tension of point c.
This reason, the conventional current flow in a resistor or wire, flows from higher tension to lower tension. Because, negatively charged objects are pulled toward higher tension, while positive change object is pulled towards lower voltages. Voltage drives current.
As an electrician, how to handle voltage?
Working on any level of voltage require professional experience, safety tools, and protective material, even in the power off state, assume there is a power this will this will keep you vigilant during your work. Make sure you avoid short-circuiting the unlike charges like two terminals of socket outlet. Always make sure you connect your device to require rated voltage.
Some American devices brought to Nigeria, have 110v and 220v. This means in America, it uses 110v but in Nigeria, it uses 220, any attempt to change the country voltage, will result in burning out your device. Do not play with voltage during electrical work. Continue to pp3
Reasons for low voltage:
Overloading the line.
Loose terminals connection.
Underrating the supply cable
Frequency drop from 50Hz
Drawing voltage to a long distance without boosting it.
Corrosion on terminals, these prevent proper contact of terminals.
 Solution
Reduce the load along the line
Use required cable size for power supply
Always tight terminal of supply very well
Use a booster station for very long distance transmission.
Lubricate the terminals with lubricant oil. All the above mention solution must be done by the qualified electrician. Safety first.
Isolate power supply always before conduction maintenance and repairs, if possible. See                                                                                                                                                             
High voltage supply can break air resistance and connect you with a live conductor.
You can limit the current flow and energy to the lower level.
Make sure you ground your distribution fuse board.
Avoid working alone on high voltage, if there is a need to switch off supply urgently, your partner can assist.
Identified rating of the voltage to work on definitions:
Voltage is the pressure from an electrical wires power supply that drives charged electrons through a conducting loop to power lighting point or device the unit of voltage is volt, drives by the Italian physicist.
An Alessandro Volta (1745-1827), who was an inventor of voltaic pile. 

References:
https://whats.com
https://en.m.wikipedia.org/wiki.voltage.com 
www.flouke.com
www.quora.com
www.instructables.com
Digital millimeter principles by Glen A. Mazur, American technical publishers.

Electric Current

INTRODUCTION:
  Is defined as the movement of chargers carrier like subatomic charged particles, for instant protons which has positive charges and electrons that have negative charges. Electric current is the measure of the follows of charge in a live conductor.
Electric current can be alternating current (AC) or direct current. The rate of flow of charges called an electric current.
Alternating current has a sine wave shape, which allowed it to have peaked and unpack point. It also has the frequency which is one circle per second the motion of electric charges is periodically returned in Ac.
 Direct current has unilateral direction does not have frequent and its polarity must maintain throughout the connections. The conventional flow terminals which contradict with electrons flow. As cross-sectional are increasing, the current also increases. In Dc, electrons move from negative to positive of the unit of electric current is in ampere (A) is the flow of 1 coulomb of charge per second or 6.24x1018 1A= 3x109esu per second (electrostatic unit of charge). but electrical and electronic devices have their  own current rating  care must  be taken in supplying  current to the device, because exceeding  its current rating is a physical  quantity  which can be express as follows:  1coulomb/ second (A)
Q = it
I = QT.
Where I = is current, measured in Ampere (A).
Q= quantity, measured in coulomb (c)
and t is time, measured in second (s).
Ampere was used as a unit of current since 1820. Dc sources Involves, battery thermocouples., solar cells, commentator and fuel cells it also flows in semiconductors, insulator, and vacuum as in ion beams movement of electrons in a given conductor was random and they move very slow be because they close to one another just like water in a pipe which called electrons to drift velocity. But when high pressure pushed electrons, it will move nearly the speed of light (186,000 miles/s.
Applications of electric current electric current are the follow of charged particle called electron together with unmovable ones called life, infect hardly to see technological development without the influence of electric current. It reaches the time of producing an electric car which I saw during the visit of Engineer Jelani Aliyu in Kebbi State.
Now, list of some application of electric current:
It uses to light our homes or industrial area.
It used to wash and dry our clothes.
It used for automatic control of garage door at the flip of the switch.
It used to conveyed information or data between long distance example telecommunication.
It is used to heat our rooms  e.g H= I 2Rt
It is used to cook foods.
Charge is quantized as double  of the electron or proton-proton charge e=1.603 x 10^-19  coulomb electron  charge –e= - 1.602 x 10^-19  

  coulomb
Discussion of electric current will not be completed unless Kirchhoff's laws stated.
First law state that the sum of electric currents entering a junction is equal to the current leaving the junction. It is a probe of the consequence of electric charge.

Second Law:
The sum of electric potential difference along any close lop in a Dc circuit is zero. This law highlight the consequence of the conservation of energy.
During the flow of electric current in a length of the conductor, don't attempt to touch it without insulator cover, otherwise heavy electric shock can flow in your body, sometimes it can kill or in cause injury. Be careful.
All the devices have their current rating, this rating n is very important to observe it and also to obey it, exceeding the current rating of the device is leading to the damaging to be a malfunction at all. Do not try to exceed the current rating of any electronic devices. It can be 1A, 3A, 5A,15A, 25A, 30A.
Electric current can be divided into two:
Direct current.
Alternating current.
Direct current (DC): is a unidirectional current it can found from the battery, solar panel, and thermocouple. It was first used as a means of transmission power lines by Thomas Edison for commercial use.
Some uses of DC.
It can be used as back up e.g  for solar cells and  some electronic devices such as mobile  phones cameras
It used in an aircraft application.
It is used in low voltage application.
It is used in automotive
It is used in special application such as sub-sea high voltage Dc transmission lines.
Demerit:
It has a high cost of forming terminal stations and switchyards.
It has limited overloading  capacity
It has the high cost of maintenance
Alternating s current  (AC) is an electric current  produced  in sine waveform,  with the ability  of voltage  switching polarity or current switching  direction  posit  and negative direction
Merit:
It has more durability and it can handle high voltage machine.
It is a source of supply to our homes and appliance  we use before, it  converted  to the DC
 It used in transmission high voltage from generating transmission stations.
It can be step up or step down according to the required need.
It is cheaper for consumers
It is cheaper in term of the transmission process.
Transformer Working Principle:
 A transformer is a device used to either step up or step down the electrical energy. Transformer playing on an important role in generation, transmission and distribution station. Let us look inside the transformer it consist of coils, namely primary coil and secondary coil immersed in oil that serve as an insulator. The coils were turned around lion core depend on the types of transformer. These metric numbers of coils determine the types of transformer.
Transformer always energies of from the primary side to the secondary site, therefore the primary side is an input part while the secondary side stands for the output part, a way of identifying types of transformer.
As stated earlier, the number of turns determines the type of transformer if the number of turns at the secondary side is greater than primary did coil, the transformer is called a step-up transformer. But if a number of turns at the secondary side is less than primary turns is called step down transformer, each type of transformer has its own design purposes.  Let start from the generation station at this station, there is a need for the step up transformer why? Because of long distance, it will take to reach transmission station. Also along the booster station step up transformer require all this to overcome, the voltage drop along the lines. At the transmission station, mostly step down transformer is required, because, the power energy (electrical) is going to transmit to various distribution station which is 33Kv. The consumers of electrical power receive their energy from the distribution station to either  industries  or residential terminals but for  residential, steps down transformer  must be used to step  down 11k to 415V, while for an industrial  layout many machines need 11kv for their operation  then other low voltage appliance  use output  of step down transformer of 11kv/415v.
Do you know the wonderful things of transformer m coils? Are they don't have physical content between it (primary and secondary coil). It connects through the induced electromagnetic force what is electromagnetic induction?  Is a process by which a current is produced as a result of changes in the magnetic field.
Below is a schematic diagram of the step up and step down transformer.
Step up transformer (Ns & N_P). Step down transformer  (Ns & N_P).
 Some uses of transformer:
It uses at generating station to step up generated voltage for instant  16kv – 333kv.
It also used at the transmission station for step down voltage.
 It uses at distribution station to step down 33kv to 11kv.
It used at the substation (11kv) to step down 11k/415v for consumers at their residential houses.
It uses in electronics devices
Transformer Types
Due to the different need for electricity, there must be different types of the transformer from generation, transmission, distribution and also in May of homes appliances. The transformer has a capability to transformer electrical energy acidly to the manufacturer specification and user need.
 I will discuss some types of transformers and their uses as follows:
Power transformer.
Step up and step down transformer
Distribution transformer
Instrument transformer
Current transformer
Potential transformer
Single phase transformer
Three phase transformer
Power Transformer:
It used in the transformer of higher voltage.
It used in generation station of electrical power.
It is large in size
Step up Transformer:
It used to rise up the voltage
It can found at generation, transformer.
 Its primary coils are less than secondary coils that are V2: V1.
It used to overcome power 105 5 along transmission line by install it at booster stations step down transformer.
 It uses in both transmission and distribution stations.
 It used to feed consumers by stepping down 11kv to 415v.
It primary coils is greater than secondary coils in this type of transformer.
It also uses in electronics device to step down 220v -12,6v, 24v.
Distribution Transformer:
It used for distribution of electrical energy to either consumer or in industries.
It has a high current low voltage.
It can be mounted or grounded type
It has the efficiency of  60% -70%
Instrument transformer: (isolation transformer).
It was subdivided in to two:
Current transformer  (CT):
Potential  transformer(voltage  transformer).
It primary coils connected to high voltage line for the purpose of measuring it.
 Its secondary winding was connected to measuring instrument and meter device
It steps down voltage level to a safe value.
Its primary winding is earthed for the safety enters its primary, to protect, measuring instrument and meter.
 Voltage transformer may have primary to secondary voltage ration as 6000: 120, this means output voltage is of 120V when inputted at primary windings.
Current Transformer
It used for measurement (current)
It used for protection
 Its primary winding is connected in series with main supply s just like ammeter.
It reduces the amount of current from primary coils to secondary like 4000:50
Sources:
 www.edinformatics.com
www.thoughtco.com
www.physicsdassroom.com
www.britannica.com/science
www.hyperphysic.edu
www.quora.com
www.toppr.com/guid/physics/electrcity

Solar Measurement Parameters

INTRODUCTION:
Solar Measurement Parameters: Measurement must put ahead in every aspect of engineering work solar energy was not exempted. There are parameters need to be observed for proper and accurate solar radiation, location and direction. Before installing solar electricity the following parameters need to be observed.
It gives you details view where to installed PVC for high radiation collection, which produces the high output.
Solar Constant:
Is the amount of solar rays received per unit time of collector area, at the mean distance of the earth from the sun on a surface, normal to the sun. It is expressed in Cm² /min.
Irradiance:
Define as the amount of solar energy felled on a surface or total amount of energy passing through an area. This gives a hint of how much of solar energy is present for the collector in an area.
In solution:
Is refers to solar irradiance received on a horizontal surface, such as the ground solar flux.
Is the sun trine at an angle?
Example:
Find the irradiance of a 9500kg of sunlight striking a 1m2 surface in 2 hours. The irradiance at any points on the surface is given by.
Irr = 9500/m² x 2 x3600 = 6.84x104 Kw/m².
How can the above solar parameter be observed? By using an instrument designed to carry out the solar observation. Some instrument will be discussed below:
The pyranometer:
Is an instrument used to measure the total flux?  From the direct rays, as well as the rays scattered by the entire hemisphere viewed by the instrument.
Note: total flux is sola called Global flux.
Shading Range Pyranometer:
Is an instrument that records only solar flare excluding direct sunlight that his scattered component of the sunlight, so that when this record is subtracted from the reading of standard pyranometer, the result is a measure of direct solar flux.
Pyranometer
 It refers to an instrument used to measure,  direct solar flux plies and a very small amount of sky included in its field. It is mounted in a manner; it can track the daily and seasonal motion of the sun.
Moving Shadow- Bar Pyrheliometer: It used to measures both direct scattered and total isolation. It was a moving shadow bar to modulate the incoming direct component of sunlight.
Sunshine Recorder: Is a device designed to records the capacity of sunstone at a per specific region, with the aimed to give the suitable location for solar energy production for powering electrical devices.

Sunshine Recorder:
It comprises glass sphere keep in a spherical bow I together with a metallic groove which keeps the record card. Sun rays refracted and focused accurately on the record card under the glass sphere, making burnt signs on the card. To measure sunshine duration, length of the burnt signs has to be observed, the card is calibrated to allow measuring hours and minute of the day.
 The sunshine recorder glass sphere was silvered inside and was put before the camera lens while the axis of the device is being placed parallel to the earth's polar axis. It used double convex lens about 90mm.
Operation of pyranometer:
 It consists of Thermopylae which makes it small less heavy low cost and continues generating of voltage output, and it is an active device because it does not require any external source control.
It operates by detection of incoming solar radiation and totally received by a horizontal dark surface, over a huge wavelength range. This makes an increase in of temperature that measured via thermocouples join in series. It consists of the hot junction that collects radiation and passive (cold) junction that serves as a heat sink.
The higher performance pyranometer is made up thermoelectric with two dissimilar semiconductors devices.
Temperature and heat are they similar?
No, the temperature is the measure of the degree of hotness or coldness of the body while heat means a total energy of molecular motion in a matter it depends on the speed of the molecules cooled cosmos. IPAC. Catechu temperature scale.
Ok = 273.15 + OC
OF = (5/9) x (OF -32)
OC = (9/5) x OC +32
To know the energy you will utilize over a period of time multiply power by hour example 40W, 2Hour is 40 x 2= 80WH.
Solar Power Introduction:
 The world experiencing consequences of climate change which seriously affecting human resources.
As are a salt of this, now a lot of countries are investing in solar energy to overcome the effect of climate change. This led to manufacturing the electric car, solar vehicles and so many electronic devices such as mobile phone and calculates. Field of electrical wiring also not left behind in a small explanation.
What is the component you need for solar election there is a lot of components, procedure and guides line to installed solar power in our homes firstly, there is a need for the solar panel, which has the photocell, that accepts solar rays, radiation as a Direct current (DC) source, it can be used inverter before they use solar power.
Before mounting the solar panel, you must estimate the load required in your resident. This will give how many solar panels require to meet require load in the residential building.
Suppose, you want to supply solar electricity to power 20buibs of 15w and you need, to use it for 6 hours daily.
Solution
P total = 15x20 = 300w
P daily = 300x 6 = 1800w
 Assuming 6 hours/ day of sunshine each day therefore, hourly = 1800/6 = 300W
Despite the effort of giant countries, to invest in advancing research in renewable energy such as solar energy up to now the components are expensive, but we hope few years ahead, everybody can benefit with solar electric everywhere in the world.
Factors must be observed before installing the solar panel that is solar array configuration.
Solar valuation.
Site Location
Availability of solar ray's radiation.
Collector
Tracking and other met logical conditions solar photovoltaic cell power generation profile.
Temperature
Wind
Moisture
Relative humidity,
I hope we are together we still talking about solar panel only this is the sign of solar electricity consist of a lot of procedures before it reaches final subcircuit, be patient just follow us. Also, there is a solar array configuration as follows.
Series connection for grid-connected  inventor or 24v
Parallel connection. Charge controller
V1
V2
V3
PVC         PVC   PVC
Series solar panel connection gives out high voltage, which current will be the same, as following      At its output two terminals are observed.
V. VT = V1 + V2 + V3.

Parallel solar panel connection. It gives out high current, and it has two parallel terminals, one for a started panel other for another end as follows:

Diodes used to block reverse voltage to the solar panel in the dark condition.
Note:

 Series connection arrangement positive connected to negative of next panel and negative terminals to another panel terminal (positive).

Parallel connection arrangement:

 Positive to positive of next solar panel and negative to negative of next solar panel. On the solar panel, there is a diode that prevents returning back of the energy stored by the backup batteries at night because diode was a unidirectional component.

 Also among the solar power components, we have array DC Disconnect is used to disconnect solar power delivery from solar panels.

System meter. It was responsible for monitoring utilized and remaining with your system. This can give hint, how to manage your energy. Charge controller (C.C).

 It controlled the batteries from overcharging, which can easily make it weak within a short period. It also blocks delivery of battery charge at certain, point, battery charge from reaching empty level charge controller has it's upper voltage limit depend on the rating of charge controller make sure you did not exceed upper voltage limit to avoid burning it. It consists of different voltage rating such as 12v, 24v. 48v and 6-60v. Also, it has 1-6A. To calculate it 3 powers: watt/ volts. An e.g. 900w/24v = 37. 5+25%

25% stand as tolerance or surplus, do not just use exact value.
Backup Battery:
Is used for backup  purposes it is clear during  night or darkness, the solar cell cannot deliver DC source  to  the connected  load battery  is used to stored  energy and can utilize it in the absence of sunshine, it can be converted  to AC battery rated as Ampere hour (AH)
Volt X AH/100 = Watt Hours
24V X 210AH/100= 50.4WH
Inverted:   is an electronic device designed to change direct current (DC) to Alternating current (AC). It receives the voltage from batteries and inverts output to AC. It has its power source to carry-out its operation.
The rating of the inverter, depending on the design of the load to power it. It rated in KVA like 16KVA  and it produces sine were output or pulse width modulation.
Most  AC motors use modified sine wave it has the standard frequency of either 50H2 or 60H2 AC output voltages is 240VAC at the distribution level the duration of an inverter can prolong by adding many batteries. Also increasing more equipment within inverter rating decrease running time of the inverter, this is opposite generator operation.
Procedure for adding batteries to inverter there is two basic types of connection of batteries
Series  connection
Parallel  connection
Series connection, the voltage will be high while the amperage remains the same.
Merit:
It gives a high output voltage.
Demerit:
 It one battery dies, other can not de live output to an inverter.
Regular change of death battery.
Parallel connection of batteries; it produces additional ampere-hour (ah) rating of the battery the voltage remains constant.
Deficiency
 If one battery discharges the other batteries will also discharge through it.
This lead to the fast discharge of the battery bank.
It leads to overcurrent within battery pack its  cause fire outbreak
The remedy of the Deficiency
Diodes can be used to isolate the discharged battery from affecting others batteries.
Automatic southing can also use to isolate discharged battery.
 Application of Inverter:
It converts DC from either batteries or fuel cell to AC power.
It uses as uninterruptible  power supplies (ups)
 It rectifier AC to DC.
It used an  electric motor speed  control
It used as inverter compressors  in the refrigerator  or air  conditioner,  to regulate system performance
It used as grid-tied inverters.
Under solar panel series connection:
What will happen, if the solar panel with distinct nominal voltage connected but with the same concentrating?
Suppose we have 3 solar panels in series with distinct nominal voltage, 7,9,10 the array delivers 26 volts at 3.0A, or 26x 3 = 78w.
What will be the result, if solar panels connected in series with distinct nominal voltage and distinct current rating?
 In this case, the amperage output will be the same with the least rating of the solar panel, which lead to reduce in arrays efficiency. This is just a way of resources.
Parallel solar panel connection, if all the panels have the nominal voltage rating e.g. 6 volts and identical 4. 0A, the amperage output of the solar panels will increase which voltage remain Constance.

 If solar panels connected in parallel form, with different nominal voltage and distinct current rating, it will give output according to the lowest voltage panel,  this leads to a huge reduction of solar panel output in short form a series connection produces high voltage output and constant amperage within the whole connection.
But parallel connection produces huge current output and constant voltage within the whole connection.
Example:
A Series Parallel solar Amoy comprises 4 rows 5 column of the solar panel each rated 25v and 5A are connected to charge a bank of solar batteries.
Find the output current, voltage, and power.
Assuming 255AH capacity battery was charged by solar Energy,
how long it takes the battery to change?
ii. Who can long battery deliver 5A constantly to a load?
Solution:
Data
Voltages:  25v/4 raws     
Current: 3A/5column
P total=?
V total= V1   + V2 + V3 + V4
 = 25+25+25+25
 = 50+50
 = 100V
I total = I1 + I2+ I3 + I4 + I5
 = 5+5+5+5+5+5
 = 15+15
 = 304
P total  = VT  IT
  = 100x 30
 = 3000w
  = 3.0kw
 How long batteries take to charge with 255AH?
255AH/30A= 8. 5 Hrs
How long battery powered load 5A?
Series-parallel connection.

References:
www.hko.gov.hk
www.pvcdrom.pveducation.org
www.kippzone.com

Software Problems of PC

INTRODUCTION:
Personal computers due their closeness to user, there is need to know some basics problems and their possible solutions. This give hint of some basics problems. Always do not neglect any change you observed in your PC,early detection of problem, make solution easy. There is many  task you can carry out using your PC,do not juck with it. Make sure Anti virus is updated, when time require.
Poor performance: this means delay in response to task given to the computer by the user. The following factors can develop poor performance of the computer:

Fragmented data.

Spyware programs.

Service software.

Corrupted register.

Virus attack.

Small RAM capacity.

Solution:

Regular clearing of registry which is needed.

Upgrading the RAM.

Using external flash as memory storage to reduce high data in computer.

Installing antivirus and upgrading it when it is stated.

It is advisable to have at least 30%of computer performance speed.

Blue Screen of Death (BSOD):

It is the critical errors that occur in window operating system. Following program can cause it:

Spyware, malware or virus

Error in drive.

Error in register or software.

Solution:

It can be identify by an 8-digital have decimal 1 number such as STOP 0x000000A.  STOP 0x0000007F.

You can use event viewer to digital these errors.

System lock up problem:

Low capacity of RAM.

Attack of virus.

Solution:

Upgrade the RAM (Random Access Memory) to high memory capacity.

Installed light capacity application to avoid filling of your computer memory

INPUT AND OUTPUT DEVICE NOT FUNCTION:

All the devices connected to computer system most have driver, it can be automatically install and configure by operating system manufacturer.

While other needs to be installed by the user, such as printer, scanner, and photocopier, they all have their drivers which allow them to communicate with operating system and carried out it required function.

Troubleshooting procedures of computer system:

Back up users data.

System approach.

Make no assumptions.

Create priorities.

Documentations.

Backup user’s data:

This is very important, because it allow restoring user’s data after carrying out troubleshooting work. This makes users comfortable with his system.

System approach:

It is very important to follow system bit by bit in an orderly many time random selecting of component during trouble shooting. Also make sure you use electrostatic discharge (ESD), because electro static can cause erasing of data.

Make no assumption:

Making assumption was always, not applicable as per as trouble shooting concern, something dust can cause system not function and all the Components were ok. At this situation firstly blow out the dust completely and power the computer system to observe its operation it may be ok.

There is time, a hardware technician tried to repair computer system and is not even powering on, they called me to check, despite am not expert hardware repair, I am still learning. I opened the CPU case, I remember the RAM can cause similar problem, I remove the RAM, I cleaned the RAM and I re-insert it, the computer system was just started booting after pressing its power button.

Establish Priorities:

It is usual, several fault can be occurred at the same time. What you suppose to do, select more priority. For instant, if there are two computer systems one did not power o at all in this situation second computer system most given priority than first one.

Documentation: this is a compiling all the necessary measure you took to solve any fault in computer system, cause of the fault ,date and time and precautions  taken by the user of computer to avoid feature occurrences of the fault. This is the really helpful and serves as reference in feature trouble shooting work.

Basic trouble shooting tools:

Troubleshooting was categorized into two:

Hardware tools.

Software tools.

Hardware tools are the physical tools they include

Screw driver.

Long-noise pliers.

Multi-Meter (Digital or Analog)

Flashlight.

Soldering iron.

Wire strippers.

Compressed air can or vacuum

Software tools and utilities:

The are tools to solve operational problem of computer system ,such as booting or incorrect configuration.

Bootable disk.

Power on self –test .

Hard drive self –test. 

Bootable disk: This helps the computer system to boot with MS-DOS. It consists of vital utilities such as format & edits command.

Power-on self-test (post): This has responsibility of detecting and testing major hardware component installed on the computer all the basic components are in good working condition if post completed successfully.

Hard-drive self-test: This can be using Microsoft diagnostic (MSD) program to test the good condition of hard disk.

Software diagnostic tools: they are use to check or monitor and test the hardware component. Microsoft diagnostic (MSD). Qaplus, Checkits and Amidag