The International Avogadro Coordination project created the world's most perfect sphere using Silicon in its crystalline form. The diameter of the sphere is $9.4 \,cm$ with an uncertainty of $0.2 \,nm$. The atoms in the crystals are packed in cubes of side $a$. The side is measured with a relative error of $2 \times 10^{-9}$, and each cube has $8$ atoms in it. Then, the relative error in the mass of the sphere is closest to (assume molar mass of Silicon and Avogadro's number to be known precisely)
$6.4 \times 10^{-9}$
$4.0 \times 10^{-10}$
$1.2 \times 10^{-8}$
$5.0 \times 10^{-8}$
Two resistors of resistances $R_1 = (300 \pm 3) \,\Omega $ and $R_2 = (500 \pm 4)$ are connected in series. The equivalent resistance of the series combination is
Explain uncertainty or error in given measurement by suitable example.
A packet contains silver powder of mass $20.23 \,g \pm 0.01 \,g$. Some of the powder of mass $5.75 \,g \pm 0.01 \,g$ is taken out from it. The mass of the powder left back is ................
A thin copper wire of length l metre increases in length by $ 2\%$ when heated through $10^o C$. ......... $\%$ is the percentage increase in area when a square copper sheet of length $l$ metre is heated through $10^o C$