<u>Answer :</u>
(a) d = 0.25 m
(b) d = 0.5 m
<u>Explanation :</u>
It is given that,
Frequency of sound waves, f = 686 Hz
Speed of sound wave at 
is, v = 343 m/s
(1) Perfectly destructive interference occurs when the path difference is half integral multiple of wavelength i.e.
........(1)
Velocity of sound wave is given by :
Hence, when the speakers are in phase the smallest distance between the speakers for which the interference of the sound waves is perfectly destructive is 0.25 m.
(2) For constructive interference, the path difference is integral multiple of wavelengths i.e.
( n = integers )
Let n = 1
So, 
Hence, the smallest distance between the speakers for which the interference of the sound waves is maximum constructive is 0.5 m.
Since the electric field between the plates is constant, If the two plates are brought closer together, the potential difference between the two plates decreases
The relation between potential difference and the electric field is given by ΔV = E.d
Since the electric field is maintained constant, the potential difference is directly inversely proportional to the distance between the plates.
The potential difference between the plates will therefore likewise decrease if the distance between the plates is reduced, we will state in this case.
The energy required to move a unit charge, or one coulomb, from one point to the other in a circuit is measured as the potential difference between the two points. Potential difference is measured in volts or joules per coulomb.
Refer to more about the potential difference here
brainly.com/question/12198573
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A higher frequency. I just got this answer on usa test prep.
Answer:
A
Explanation:
A and B are isotopes of one another but the same element
C and D are isotopes of one another but the same element
However, A and B have a different proton count than C and D, indicating different elements because the proton count is equivalent to the atomic number.
