Answer:
Energy cannot be changed from one form to another without a loss of usable energy
Explanation:
Second law of thermodynamics states that the total entropy or the randomness of the system remains constant over time. It also states that the net entropy will remain the same or it will increase.
Entropy of a system is given by heat absorbed divided by temperature. It is given by :
So, the correct option is (A) "Energy cannot be changed from one form to another without a loss of usable energy".
'C' is the only true statement on the list.
Step-up voltage transformers have a lower number of turns
in the primary than in the secondary winding.
Answer:
A. Speed
Explanation:
A vector quantity is a quantity which has both magnitude and direction. Here in the given options, speed is a scalar quantity but not the vector quantity.
Answer:
44100 N
Explanation:
Each wall will have dimension of 4 m x 1.5 m
Whole force will act on central point of wall situated at a depth of 1.5 /2 = .75m
pressure at CM = h d g , h = .75 , d ( density of water = 10³ )
pressure at CM = .75 x 10³ x 9.8
= 7350 N / m²
Total force on each wall
= pressure x area
= 7350 x 4 x 1.5
= 44100 N Ans
b ) If h = 1.5 x 2 = 3
Pressure = hdg
1.5 x 10³ x 9.8
= 14700 N / m²
Force
= pressure x area
14700 x 3 x 4
= 176400 N
Which is 4 times 44100 N
So force will quadruple.
It is so because both area and height have become twice.
K=1400*V^2/2
K=20000*25^2/2. => 1400*V^2/2=20000*25^2/2 <=> 1400*V^2=20000*25^2
14*V^2=200*225
v^2=100*225/7
v=250/7^(1/2)
Answer: 250*7^(1/2)/7
