Explanation:
The given data is as follows.
Magnetic field strength (B) = 0.65 T
Speed (v) = 2.3 m/s
Induced emf (E) = ?
Formula for emf induced at the ends of the rod of length L which is moving with a speed of v is as follows.
E = BvL
Putting the given values into the formula as follows.
![E_{1} = BvL](https://tex.z-dn.net/?f=E_%7B1%7D%20%3D%20BvL)
=
= 1.495 L .............. (1)
When magnetic field is changed to
= 0.48 T
Now, we assume that the speed be
to get the emf
.
Then,
= 3.11 m/s
Therefore, we can conclude that the speed v of the rod be adjusted to reestablish the emf induced between the ends of the rod at its initial value is 3.11 m/s.
Answer:![T_L=-154.2^{\circ}](https://tex.z-dn.net/?f=T_L%3D-154.2%5E%7B%5Ccirc%7D)
Explanation:
Given
COP= 60 % of carnot heat pump
![COP=\frac{60}{100}\times \frac{T_H}{T_H-T_L}](https://tex.z-dn.net/?f=COP%3D%5Cfrac%7B60%7D%7B100%7D%5Ctimes%20%5Cfrac%7BT_H%7D%7BT_H-T_L%7D)
For heat added directly to be as efficient as via heat pump
![Q_s=W](https://tex.z-dn.net/?f=Q_s%3DW)
![COP=\frac{Q_s}{W}=\frac{60}{100}\times \frac{T_H}{T_H-T_L}](https://tex.z-dn.net/?f=COP%3D%5Cfrac%7BQ_s%7D%7BW%7D%3D%5Cfrac%7B60%7D%7B100%7D%5Ctimes%20%5Cfrac%7BT_H%7D%7BT_H-T_L%7D)
![1=\frac{60}{100}\times \frac{T_H}{T_H-T_L}](https://tex.z-dn.net/?f=1%3D%5Cfrac%7B60%7D%7B100%7D%5Ctimes%20%5Cfrac%7BT_H%7D%7BT_H-T_L%7D)
![1=\frac{60}{100}\times \frac{24+273}{24+273-T_L}](https://tex.z-dn.net/?f=1%3D%5Cfrac%7B60%7D%7B100%7D%5Ctimes%20%5Cfrac%7B24%2B273%7D%7B24%2B273-T_L%7D)
![T_L=118.8 K](https://tex.z-dn.net/?f=T_L%3D118.8%20K)
![T_L=-154.2^{\circ}](https://tex.z-dn.net/?f=T_L%3D-154.2%5E%7B%5Ccirc%7D)
Answer:
-34.5 W
Explanation:
rate of heat transfer = Stefan-Boltzmann constant x emissivity x surface area x temperature^4
![P = \alpha eA(T_{f} ^{4}- T_{i} ^{4}) = 5.67*10^{-8} *0.205*1.5(256^{4} - 284.4^{4} ) = -34.5 W](https://tex.z-dn.net/?f=P%20%3D%20%5Calpha%20eA%28T_%7Bf%7D%20%5E%7B4%7D-%20T_%7Bi%7D%20%5E%7B4%7D%29%20%3D%205.67%2A10%5E%7B-8%7D%20%2A0.205%2A1.5%28256%5E%7B4%7D%20-%20284.4%5E%7B4%7D%20%29%20%3D%20-34.5%20W)