MY CART (5)

ITEM
DETAILS
MRP
DISCOUNT
FINAL PRICE
Total Price:

There are no items in this cart.
Continue Shopping
                   

i often confused how to relate  between speed, torque, current, and voltage in a dc machine. for example when ew write the power equation P= 2(pi)NT/60 =VI.


from this eqation can I consider both N and T are directly related to current?


I know that the answer is NO. because N and T are always inversly related. but why?


can any one please cleare my confusion.

4 years ago

Share

Answers : (2)

                                        

Dear student,


Here is the basic principle for your understanding:


he force F on a wire of length L carrying a current i in a magnetic field B is iLB times the sine of the angle between B and i, which would be 90° if the field were uniformly vertical. The direction of F comes from the right hand rule*, as shown here. The two forces shown here are equal and opposite, but they are displaced vertically, so they exert a torque. (The forces on the other two sides of the coil act along the same line and so exert no torque.)



    * A number of different nmemonics are used to remember the direction of the force. Some use the right hand, some the left. For students who know vector multiplication, it is easy to use the Lorentz force directly:  F  =  q v X B ,  whence F  =  i dL X B . That is the origin of the diagram shown here.

The coil can also be considered as a magnetic dipole, or a little electromagnet, as indicated by the arrow SN: curl the fingers of your right hand in the direction of the current, and your thumb is the North pole. In the sketch at right, the electromagnet formed by the coil of the rotor is represented as a permanent magnet, and the same torque (North attracts South) is seen to be that acting to align the central magnet.


 

















Please feel free to ask your queries here. We are all IITians and here to help you in your IIT JEE preparation.


All the best.


Win exciting gifts by answering the questions on Discussion Forum. So help discuss any query on askiitians forum and become an Elite Expert League askiitian.


Now you score 5+15 POINTS by uploading your Pic and Downloading the Askiitians Toolbar  respectively : Click here to download the toolbar..


 


Askiitians Expert


Sagar Singh


B.Tech, IIT Delhi
















4 years ago
                                        

dear student,


DC motors are the simplest type; given a constant voltage, they run to a steady speed and steady current (electric torque= constant * current for DC motors).

If you need to control the torque (current), you use a current sensor (a resistor) as feedback to control the current.

If you need to control the speed, you use a speed sensor (tachometer, encoder etc) as a feedback to control the speed


Don’t forget to approve the answer if it is beneficial to you… !!


We are all IITians and here to help you in your IIT JEE preparation.


Now you can win exciting gifts by answering the questions on Discussion Forum. So help discuss any query on askiitians forum and become an Elite Expert League askiitian.


Now you score 5+15 POINTS by uploading your Pic and Downloading the Askiitians Toolbar : Click here to download the toolbar.. 


AMAN BANSAL               

4 years ago

Post Your Answer

More Questions On Electromagnetic Induction

Ask Experts

Have any Question? Ask Experts

Post Question

 
 
Answer ‘n’ Earn
Attractive Gift
Vouchers
To Win!!!
Click Here for details
Find the electric force between two protons separated by a distance of 1 fermi (1 fermi = 10-15 m). The protons in a nucleus remain at a separation of this order.
 
 
Sol. Charge on each proton = a= 1.6 10^-19 coulomb Distance between charges = 10 * 10^-15 metre = r Force = kq^2/r^2 = 9 * 10^9 * 1.6 * 1.6 * 10^-38/10^-38 = 9 * 2.56 * 10 = 230.4 Netwon
  img
Jitender Pal 11 months ago
 
force is given by putting all the values F= 230.4 newtons Thanks and Regards Apoorva Arora IIT Roorkee askIITians Faculty
  img
Apoorva Arora 11 months ago
 
Hello Thanks & Regards Arun Kumar Btech, IIT Delhi Askiitians Faculty
  img
Arun Kumar 11 months ago
how to find direction of current in lenz law????
 
 
Thanks & Regards, Nirmal Singh Askiitians faculty
  img
Nirmal Singh. one year ago
why does moving electric field creates magnetic field ?
 
 
thats all about electromagnetic waves.the elecric and magnetic fields and waves are interrelated. The fact is, magnetism is nothing more than electrostatics combined with special relativity....
 
yash kulshrestha one year ago
Under the influence of a uniform magnetic force a charge particle is moving in a circle of radius R with constant speed. the period of motion depends on .................?
 
 
Time Period of the motion is : 1) directly proportional to the mass of the charge particle , 2) inversely proportional to the charge of the particle, 3) inversely proportional to the...
 
Bikram Kumar Panda one year ago
 
Inversely propotional to the magnetic force
 
rishabh one year ago
Aiims preparation in these days..?
 
 
Attempt only previous years papers only...and take tests 2 times a day...
  img
Saurabh Kumar 2 days ago
Explain why the magnetic field lines inside a bar magnet is from south pole to north pole ? I am a class 10 student,so explain in simple words. I
 
 
The field lines represent the path that a positive magnetic charge would follow under the influence of a magntic field. Thus a unit magnetic charge, would move from south to north pole. Thus...
 
shubham sharda 20 days ago
 
The field lines are from north pole to south pole outside the magnet. We know that magnetic lines are continuous curves. So inside the magnet they should be from south to north pole in order...
 
Shubham Singh 20 days ago
View all Questions »