Which is best positive feedback or negative feedback?
Obviously,it depends on the situation.
consider a transistor amplifier.To minimize the change in collector current with respect to temperature,collector to base bias is used . This circuit uses a NEGATIVE FEEDBACK in order to compensate the rise in output current with temperature.
But in order to achieve maximum gain, the same circuit can use POSITIVE FEEDBACK by connecting the amplified output to the input .
Tire tread is 205 MM wide or 8 inches
Side wall height is 40 % of tread width or 81.7 mm or 3.2 inches
Wheel size is 17 inches
Overall tire height is 23.4 inches or 595 mm
How do you cross file and draw file?
Cross filing is done by pushing the file backwards and forwards at a slight angle to remove as much material as possible as quick as possible. Draw filing is done by using the file sideways along the edge of a piece to produce a good finish an remove very little material
How do you calculate angles from tube bending XYZ coordinates?
It is the analytic geometry formula for finding the angle between two planes.
How could the performance of a solar water heater be improved?
panels for solar water heating should be mechanical, they should rotate on a fixed axis driven by timed electical use by motor, the panel should also tip, this should be done to keep the sunlight impact as nearly perpindicular to the panel back as possible. Also if abs is being used it should be laid horizontally instead of vertically, there must be a slight upward bending of the cross pieces to facilitate drainage if necessary. This configuration will drive itself to a degree, also the water will spend the longest time in the greatest heat at the top of the panel.
What is the Difference between carbon steel and hi speed steel?
carbon steels are steels which contain upto 2% carbon and some other trace elements such as silicon, manganese etc.,
Tool steels have greater amount of alloying than the alloy steels of iron. alloying elemnts include chromium, tungsten, molybdenum, carbon, vanadium, nitrogen in the form of nitrides, manganese, silicon, cobalt.
These two mainly differ in the pattern in which they are manufactured. tool steels are manufactured from electric furnace techniques where as most carbon steels are manufactured from conventional melting processes. This is done to exhibit good alloy characteristics and impart greater refined structure which cannot be obtained from the conventional say a cuppola furnace or a bessemer furnace.
What is boiler instrumentation?
There could be an elaborate answer !
In short - for an efficient, reliable, and safe boiler operation, there is a need of basic instrumentation.
1. Safe sequence of motors and control devices.
2. Air fuel ratio control. Fuel measurement meter.
3. Inlet water flow measurement and control to maintain safe water level. Mobrey switch or suitable level switch or transmitter. Water flow meter.
4. Differential steam pressure control - pressure switch or pressure transmitter.
5. Firing sequence controller.Purging sequence. Flame detection and ignition control.
6. Two element or three element water level control method.
7. Safety valves.
8. Fuel tank level control if not gas used.
9. Dearator level control, deareator pressure / temp control
10. Alarm and trip limits and control
11. Suitable control cabinet with PLC or hardwired logic and devices and suitable user interface / HMI
12. Exhaust temp, and other sox, nox measurement.
13. Blow down method and control.
14. Intet water quality monitoring and control.
If coal or bio mass used there will more add on instrumentation and control necessary.
What is frequency dead band in turbine control system?
it is range of frequency variation for which governor does not take any proportional corrective action.
How do you calculate load factor of gear box?
K Factor
Also called an Overhung Load Factor. A constant used to modify the overhung load rating of
a gearbox based on the type of load applied on the shaft. Use the K factor either to increase
the calculated overhung load, or to reduce the gearbox overhung load rating.
Is there any motorised shut off valve available?
There are many kinds depending on the fluid to be controlled, piping considerations, etc. Please consult google; possible search term: 'powered shut off valves'.
What percentage of crude steel produced is actually recycled material?
According to the Sustainability Report of the World Steel Industry 2005, 42% of crude steel is actually recycled material.
Performance criteria is a guideline used to grade a performance. It is a description of things that must be considered to determine the grade.
What is Difference between static and dynamic pages?
Just what is the Difference Between a Static and a Dynamic IP Address you ask?
Well the IP address from your ISP is assigned in just one of two ways:
Because a static IP can be relied on for an indefinite period, some networking software requires a static IP.
ISPs usually charge extra for static IPs.
Your ISP may not be willing to give customers static IP addresses at all.
Dynamic IPs are used in large networks where computers are frequently reconfigured, or where a limited number of IP address are available to share between many computers.
How do you calibrate the muffle furnace?
use a reference digital thermometer with a probe that can measure 1800C. actually use 5 probes to measure the different areas inside the chamber...measure then compute for the uncertainties....
Technically, conveyors are anything that moves materials. More commonly they are rubber/fabric belts that rotate around rollers and carry items. There is usually one at every grocery checkout.
How do you size water softener?
Water softeners are sized by considering several factors: the peak flow rate (gallons per minute), plumbing size in the building, the hardness (measured in grain of hardness per gallon) of the incoming water, and peak daily water usage.
If the diameter of the cylinder is too large, a phenomenon called channelling may occur which causes the water softener to malfunction. If the diameter of the cylinder is too small, the flow rate through the softener can be restricted which can cause an excessive pressure drop across the system.
The overall capacity required (in grains) is determined by the required amount of water to be treated between regeneration cycles (in gallons) times the hardness of the feed water (in grains per gallon).
If the overall capacity of the water softener is too small, the system will regenerate too often. In a single tank unit, insufficient capacity can cause the softener to regenerate at the wrong time of day, which will either bypass the unit or cut off the product water supply, depending on the model. In a dual alternating unit, this problem is eliminated by having one tank in service while the other is regenerating. However, operating costs can be much higher for a unit that is too small for the application.
If the overall capacity is too large, the system will be needlessly expensive.
Additional factors such as chlorine or iron in your feed water can significantly affect the system that you should choose. It is generally best to consult an experienced water treatment professional to determine the correct system for your application.
What is the most important material in pressure cooker?
Stainless steel; because it is non-reactive, durable, and can be used on any and all heat sources.
How much heat can a firefighter suit stand?
Structural firefighting gear isrecommended by the NFPA (National Fire Protection Association) to be rated at a minimum of a TPP (Thermal Protective Performance) rating of 35. A good rule of thumb for translating a TPP rating into time in heat is to cut your TPP rating in half, this is the number of seconds you have in 1,000 degrees.
This means that we have about 18 seconds to in a room of 1,000.
An average temperature that we withstand in a structure fire is usually between 400 and 800 degrees.
With this heat resistence is also a big limitation. Though, we have protection from most heat transfer, we have little to no protection from steam. This penetrates right into the suit, and causes very painful burns.
Difference between seamless and erw pipe?
ERW (Electric Resistance Welding) pipe is manufactured by rolling metal and then welding it longitudinally across its length. Seamless pipe is manufactured by extruding the metal to the desired length; hence ERW pipe has a welded joint in its cross-section, while seamless pipe does not have any joint in its cross-section through-out its length.
I guess it depends on whether it's sealed or not.
If it's open to the atmosphere how can it be under pressure ?
If it's sealed it could be put under (positive or negative) pressure so would be, by definition, a pressure vessel IMHO.
What is the difference between an inventory coordinator and an inventory analyst?
To my opinion Inventory coordinator is a person who monitors the material movement from one place to another (intransit stock monitor) untill it reaches from source to destination
AND
Inventory analyst is a person who take the physical stock of inventory and places the order or prepare a report/decision that which inventory to be sent or to be received. Also ageing of the stock etc.
Why do we need to wear corporate attire?
If you value your job you will wear what is advised by your company.
Many companies insist on corporate attire because it gives a more professional image. Wearing a certain standard of dress, upon which there can be no disagreement (which is what coporate attire does) is projects to the community a certain image which reflects the mission statement of the company.
What is difference between orthogonal cutting and oblique cutting?
orthogonal cutting is a 2D cutting having 2 forces i.e cutting force and feed force where as oblique cutting is a 3D cutting having additional force i.e radial or passive force.