Answer:
option A
Explanation:
Given,
wavelength of light,![\lambda = 560\ nm](https://tex.z-dn.net/?f=%20%5Clambda%20%3D%20560%5C%20nm)
refractive index of gasoline, n₁ = 1.40
Refractive index of water, n₂ = 1.33
thickness of the film, t = ?
Condition of constructive interference is given by
![2 n t = (m+\dfrac{1}{2})\lambda](https://tex.z-dn.net/?f=2%20n%20t%20%3D%20%28m%2B%5Cdfrac%7B1%7D%7B2%7D%29%5Clambda)
For minimum thickness of the film m = 0
From the question we can clearly observe that phase change from gasoline to air
so, n = 1.4
![2 \times 1.4 \times t = \dfrac{560}{2}](https://tex.z-dn.net/?f=2%20%5Ctimes%201.4%20%5Ctimes%20t%20%3D%20%5Cdfrac%7B560%7D%7B2%7D)
![t = 100\ nm](https://tex.z-dn.net/?f=%20t%20%3D%20100%5C%20nm)
Hence, the correct answer is option A
Answer:
d. all of the above
Explanation:
a) Absolute dating technique is used to determine the age of rocks and fossil fuels, by the use of radioactive elements, such as, Carbon-14. The process involves the measurement of life of fossils through the remaining amount of radioactive element. It is possible by the knowledge of half life of radioactive element.
b) The radioactive isotope of Cobalt (Cobalt-60) is used to treat localized cancer. Other radioactive elements are also used to kill bacteria and treat cancer, such as, Iodine-131 is used to treat thyroid cancer
c) Radioactive elements are also used as tracers, such as Sodium-24, which is used as a tracer in blood. Other radioisotopes of Hydrogen, Carbon. Phosphorus and Sulfur, etc, are also used as tracers in different chemical reactions.
<u>Thus, all the given options are correct and the correct option is all of the above (d).</u>
Answer: 996m/s
Explanation:
Formula for calculating velocity of wave in a stretched string is
V = √T/M where;
V is the velocity of wave
T is tension
M is the mass per unit length of the wire(m/L)
Since the second wire is twice as far apart as the first, it will be L2 = 2L1
Let V1 and V2 be the speed of the shorter and longer wire respectively
V1 = √T/M1... 1
V2 = √T/M2... 2
Since V1 = 249m/s, M1 = m/L1 M2 = m/L2 = m/2L1
The equations will now become
249 = √T/(m/L1) ... 3
V2 = √T/(m/2L1)... 4
From 3,
249² = TL1/m...5
From 4,
V2²= 2TL1/m... 6
Dividing equation 5 by 6 we have;
249²/V2² = TL1/m×m/2TL1
{249/V2}² = 1/2
249/V2 = (1/2)²
249/V2 = 1/4
V2 = 249×4
V2 = 996m/s
Therefore the speed of the wave on the longer wire is 996m/s
A frequency spectrum shows a tone that is composed of a frequency of 440 h z, 880 h z, and 1320 h z. the 880 h z and 1320 h z frequencies are called. sine wave.
Frequency, in physics, the wide variety of waves that skip a hard and fast point in unit time; also, the variety of cycles or vibrations gone through for the duration of one unit of time via a body in periodic movement.
The variety of durations or often happening occasions of any given type in unit of time, typically in one 2nd. the variety of cycles or finished alternations in keeping with unit time of a wave or oscillation. symbol: F; Abbreviation: freq.
Frequency is an crucial parameter used in technological know-how and engineering to specify the temporal charge of change located in oscillatory and periodic phenomena, along with mechanical vibrations, audio indicators, radio waves, and mild.
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