Saved Bookmarks
| 1. |
Suppose the loop is stationary but the current feeding the electromagnet that produces the magnetic field is gradually reduced so that the field decreases from its initial value of 0.3 T at the rate of 0.02 T s^(-1). If the cut is joined and the loop has a resistance of 1.6 Omega, how much power is dissipated by the loop as heat ? What is the source of this power ? |
|
Answer» Solution :Induced emf, `epsilon=-(dphi)/(dt)` `THEREFORE epsilon=-d/(dt)(AB cos 0^@)(because vecA||vecB)` `=-A(dB)/(dt)` `=-(8xx10^(-2)xx2xx10^(-2))(-0.02)` `therefore epsilon=3.2xx10^(-5)` V Power dissipated in the form of HEAT, `P=epsilon^2/R` `=(3.2xx10^(-5))^2/1.6` `therefore P=6.4xx10^(-10)W` (watt) Magnetic field changing with time is an external source to produce this power. |
|