P represents radiation pressure, c represents speed of light and S represents radiation energy striking per unit area per sec. The non-zero integers x, y, z such that Pˣ Sʸ cᶻ is dimensionless, are
Correct Answer :
x=1,y=-1,z=1
Solution :
To find the non-zero integers , , and such that the expression is dimensionless, we first determine the dimensional formulas for each of the physical quantities involved.
1. Radiation Pressure ():
Pressure is defined as force per unit area.
2. Radiation Energy striking per unit area per second ():
This quantity represents energy per unit area per unit time.
3. Speed of Light ():
Since is a speed, its dimensional formula is:
Now, we require the product to be dimensionless, which means:
Substitute the dimensions of , , and into the equation:
Combining the exponents for , , and on the left-hand side:
By equating the powers on both sides, we obtain a system of three linear equations:
1) For :
2) For :
3) For :
Let us check the third equation by substituting and :
This confirms that the relations and are consistent.
Setting , we find:
Thus, the non-zero integers that make the expression dimensionless are , , and .
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