Question

the great wall is one of the biggest statue (true or false)​

Answer 1

Answer:

true

Explanation:

the great wall is the china's structure and the biggest statue

Answer 2

$Correct Question: \\ </p><p></p><p>Resistance of a metal wire of length 1 m is \\ 26 Ω at 20°C. The diameter of the wire is \\ 0.3 mm, what will be the resistivity of \\ metal at that temperature? \\ </p><p></p><p>Using Table 12.2, predict the material of \\ the wire. \\ </p><p></p><p>Given: \\ </p><p>Resistance (R) = 26 Ω \\ </p><p></p><p>Diameter of wire (d) = 0.3 mm = \sf 3 \\ \times 10^{-4} \ m3×10−4 m \\ </p><p></p><p>Length of wire (l) = 1 m \\ </p><p></p><p>To Find: \\ </p><p></p><p>★ Resistivity of metal at 20°C \sf (\rho)(ρ)</p><p></p><p>★ Material of the wire</p><p></p><p>Answer:</p><p></p><p>Resistivity of metallic wire is given as:</p><p></p><p>\boxed{ \boxed{ \bf{ \rho = \dfrac{RA}{l} }}}ρ=lRA</p><p></p><p>A → Area of cross-section of wire \sf \dfrac{\pi d^2}{4}4πd2</p><p></p><p>So,</p><p></p><p>\bf \rho = \dfrac{R\pi {d}^{2} }{4l}ρ=4lRπd2</p><p></p><p>By substituting values we get:</p><p></p><p>\begin{gathered}\rm \implies \rho = \dfrac{26 \times 3.14 \times {(3 \times {10}^{ - 4}) }^{2} }{4 \times 1} \\ \\ \rm \implies \rho = \dfrac{26 \times 3.14 \times 9\times {10}^{ - 8}}{4 } \\ \\ \rm \implies \rho = \dfrac{ 734.76 \times {10}^{ - 8}}{4 } \\ \\ \rm \implies \rho = 183.69 \times {10}^{ - 8} \\ \\ \rm \implies \rho = 1.84 \times {10}^{ - 6} \: \Omega \: m\end{gathered}⟹ρ=4×126×3.14×(3×10−4)2⟹ρ=426×3.14×9×10−8⟹ρ=4734.76×10−8⟹ρ=183.69×10−8⟹ρ=1.84×10−6Ωm</p><p></p><p>\therefore∴ \boxed{\mathfrak{Resistivity \ of \ metal \ at \ 20\degree C \ (\rho) = 1.84 \times 10^{-6} \ \Omega \ m}}Resistivity of metal at 20°C (ρ)=1.84×10−6 Ω m</p><p></p><p>From Table 12.2 of Class - 10 NCERT Chapter - 12 Electricity (Attached)</p><p></p><p>\boxed{\mathfrak{Material \ of \ the \ wire = Manganese}}Material of the wire=Manganese</p><p></p><p>$