Answer:
Number of turns per unit length will be 
Explanation:
We have given that strength of the magnetic field produced by the solenoid B = 7 T
Current in the solenoid i = 200 A
Let the number of turns per unit length is n
Magnetic field due to solenoid is given as
here
is permeability of free space n is number of turns per unit length and i is current
So 

Answer: Resonance in sound is when one object is vibrating at the same frequency to the second object of forces to the second frequency.
Explanation:
"Acoustic resonance is a phenomenon in which an acoustic system amplifies sound waves whose frequency matches one of its own natural frequencies of vibration (its resonance frequencies)." wikipedia I hope this helps you!
C. 4 N is the answer if not then i be dumb!!!
Answer:
a. 572Btu/s
b.0.1483Btu/s.R
Explanation:
a.Assume a steady state operation, KE and PE are both neglected and fluids properties are constant.
From table A-3E, the specific heat of water is
, and the steam properties as, A-4E:

Using the energy balance for the system:

Hence, the rate of heat transfer in the heat exchanger is 572Btu/s
b. Heat gained by the water is equal to the heat lost by the condensing steam.
-The rate of steam condensation is expressed as:

Entropy generation in the heat exchanger could be defined using the entropy balance on the system:

Hence,the rate of entropy generation in the heat exchanger. is 0.1483Btu/s.R