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Explain supplementary quantities and their unit of SI system. |
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Answer» Solution :There are two SUPPLEMENTARY quantities of SI system. (1) PLANE angle `d theta(2)` Solid angle `d Omega` (1) Plane angle `d theta` : Ratio of arc of CIRCLE and radiusof circle is called plane angle `(d theta)`  From figure plane angle `d theta=("arc")/("radius")(AB)/(r)=(ds)/(r)` Plane angle subtended at centre by arc of circle having length equal to radius is called 1 radian. It is represented as rad. Maximum value of plane angle is `2pi` rad If AB= r then `theta=1` rad `[1^(@)=(pi)/(180) "rad"] and [1 rad=(180)/(pi)` degree] (2) Solid angle ` dOmega:` d by area `(DELTAA)` on spherical surface with centre of sphere is called solid angle `dOmega`  From figure, Solid angle `d Omega=("area")/(("radius")^(2))=(DeltaA)/(r^(2))` Maximum value of solid angle is `4PI` Angle subtended on `1 m^(2)` area on sphere of 1 m radius is called 1 steradian. Its symbol is Sr. If `DeltaA=1m^(2) and r=1 m "then" Omega=1` Sr |
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