Aportion of nichrome wire of radius3.70mm is to be used in winding a heating coil. if the coil must draw a current of9.85a when a voltage of 120 v is applied across its ends, find the following. (take the resistivity of nichrome to be1.50a portion of nichrome wire of radius3.70mm is to b10-6? ? ) the required resistance of the coil(b) the length of wire you must use to wind the coil.

To develop this problem it is necessary to have the concepts related to Ohm's law and resistivity.

Ohm's law is defined by the equation

Where

R=Resistence

I = current

V= Voltage

While the resistivity equation is given by

Where

resistivity

A= cross-section area

R= Resistance

L=Lenght of wire

A) We can find the resistence re-arranging our first equation, so

B) From our second equation we can re-arrange for L, so

given data:

determine the horse power (h.p) = ?

force applied to move the box(f) = 10 pounds,

box lifted from a distance         (d) = 3 feet

time taken to lift                         (t) = 10 sec,

the horse power is defined as amount of work required to move a load. the horse power is equal to 550 foot-pound per second

                  1 h.p   = 550 foot-pound/second

it can also be defined as the the load that need to be move a body for certain distance in a certain amount of time.

mathematically,

                      h.p = (force × distance)/ time

                            = (10 × 3)/ 10

                            = 30/10

                            = 3 foot -pound/sec

hence, the horse power is needed to move the box is 3 foot-pound/second

important note: 1 h.p = 550 foot-pound/second = 746 watts

i guess it’s a and b