Answer:
Explanation:
Efficiency of a Carnot engine = 1 – (T2/T1)
;
where T1 = source temperature and T2 = sink temperature
T2 = 10⁰C = 273+10 = 283K
The initial efficiency = 40%
So 0.4 = 1 - (283/Initial T1)
Initial T1 = 283/(1-0.4) = 471.67 K
To raise efficiency to 65%
0.65 = 1 - (283/Increased T1)
Increased T1 = 283/(1-0.65) = 808.57 K
The source temperature must be increased by 808.57 - 471.67 = 336.9 K or 336.9°C.
When air is blown into the open pipe,
L = 
where nis any integral number 1,2,3,4 etc. and λ is the wavelength of the oscillation
⇒λ=
Note here that n=1 is for fundamental, n=2 is first harmonic and so on..
⇒ third harmonic will be n=4
Given L=6m, n=4, solving for λ we get:
λ=
=3m
Relationship of frequency(f), velocity of sound (c) and wavelength(λ) is:
c=f.λ Or f= 
⇒f=
≈115 Hz
Answer:
Under normal conditions, a magnetic material like iron doesn't behave like a magnet because the domains don't have a preferred direction of alignment. On the other hand, the domains of a magnet (or a magnetized iron) are all aligned in s specific direction.
Answer:
What interference occurs when two waves are out of phase?
Image result for ______ interference occurs when two waves are out of phase.
Destructive interference
Destructive interference occurs when the maxima of two waves are 180 degrees out of phase: a positive displacement of one wave is canceled exactly by a negative displacement of the other wave. The amplitude of the resulting wave is zero.