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Q.

QUIZ -- A DC motor is necessary for what ?

Tags: sports, electronics, science
Asked by truth exposed, 28 Oct '12 12:06 pm
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Answers (5)

1.

Alternating-current (AC) and direct-current (DC) motors have traditionally served distinctly different applications due to their construction and inherent operating characteristics. In general, AC motors were smaller, less expensive, lighter and more rugged than DC motors. DC motors, on the other hand, operated better in variable-speed applications, particularly those requiring wide speed ranges, and provided more precise speed control.

DC motors have been the workhorse of industry in many applications where variable-speed operation is needed. In these applications, DC motors are reliable and provide precise speed control under variable operating conditions. However, DC motors are expensive to purchase and to maintain. In addition, over the past 10 years, AC drives have improved to the point where their speed control is far more precise, rivaling that of servo drives. What's more, the AC motor and drive together often cost about the same price as the DC motor alone.

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Answered by jameel ahmed, 28 Oct '12 12:33 pm

 
  
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2.

When you can get direct current a DC motor is used....but now a days you know we cant use as the current situation is bad and lots of power cut! so we use the current power - alternating current (AC)!!! hahahhaha
Answered by MS Prasad, 28 Oct '12 12:12 pm

 
  
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3.

Mota hisab samjho, railway ke diesel engine me DC generator hi laga rehta hai. jo lambi si lambi train kheench le jaata hai. load capacity.
Answered by sharad sharad, 28 Oct '12 06:59 pm

 
  
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4.

There are three general types of D.C. motor control: manual, semi-automatic and automatic. Manual control directly connects a D.C. motor to the input power line or mains. Operator intervention is required. 5 Semi-automatic control uses switches or sensors (.e.g., limit, pressure, temperature, float level, flow, proximity, timing and photo-sensitive switches) 6 to control a magnetic contactor or starter which, when enabled or closed, will connect the motor to the input power line. 7 In semi-automatic operation, an operator is needed to start or stop the motor but the rest of the operation is controlled by the sensors or switches. Automatic control is similar to semi-automatic control with one important difference: no operator intervention is required. For example, a thermostat in an air conditioning system or a refrigerator will turn a compressor motor on or off to maintain the setpoint temperature automatically.
Source: google search
Answered by anil garg, 28 Oct '12 06:55 pm

 
  
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5.

A DC motor is an electric motor that runs on direct current (DC) electricity. DC motors were used to run machinery, often eliminating the need for a local steam engine or internal combustion engine. DC motors can operate directly from rechargeable batteries, providing the motive power for the first electric vehicles. Today DC motors are still found in applications as small as toys and disk drives, or in large sizes to operate steel rolling mills and paper machines. Modern DC motors are nearly always operated in conjunction with power electronic devices.
Answered by lakhan pandey, 28 Oct '12 12:33 pm

 
  
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