Question help

[Kiwi k]

any help with this greatly appreciated..the output of a series dc motor when connected to a 230v supply and running at 1320 rev/min is 3.5kw. the supply current for this loading is 20.5A

1.calculate torque developed
2. Operating efficiency

 

[Pete999]

any help with this greatly appreciated..the output of a series dc motor when connected to a 230v supply and running at 1320 rev/min is 3.5kw. the supply current for this loading is 20.5A

1.calculate torque developed
2. Operating efficiency

Far to early in the day for questions like this LOL

 

[David Prosser]

τ = (I * V * E *60) / (rpm * 2π)

E = Pout / Pin

You have all the information you need for these two equations in the question. So just make sure you follow the rules of what order you carry out pressing the buttons on your calcualtor (or by a fancy one you type it all in).

 

[FatAlan]

BODMAS?

 

[Lucien Nunes]

Mechanical power is the product of torque and angular velocity. You have the output power and the speed in rpm so you can convert speed into angular velocity and hence find the torque.

Efficiency is the ratio of output power / input power. So again use the stated output power and find the input power from current and voltage.

If you want further guidance please show your working so far...

 

[David Prosser]

BODMAS?

BIDMAS

 

[FatAlan]

Brackets, Of, Divide, Multiply, Add, Subtract. What I was taught about 35 years ago but I'm sure a mathematician will correct me.

 

[David Prosser]

Brackets, Of, Divide, Multiply, Add, Subtract. What I was taught about 35 years ago but I'm sure a mathematician will correct me.

Brackets, Indices, Division and Multiplication, Addition and Subtraction.

Same thing.

 

[FatAlan]

Bod sounds better. ;-)

 

[The Ghost]

Brackets, Ordinances (powers) as I was taught it.

 

[telectrix]

better still, get someone else to work it out.

 

[Kiwi k]

thanks everyone for the help