Resistance of a wire is given by R = ρ L/A . When stretched, L ′ = 1.5L and = A/(1.5)², so new resistance: R ′ = ρ 1.5L/A/(1.5)² = 2.25R To make R′ = 4R, solving gives fraction 1/6. ...
Discussion Forum Latest Questions
The energy gained by an electron in an electric field E over a mean free path l is given by: eEl = 2 eV Solving for E: E = 2 × 1.6 × 10⁻¹⁹ /4 × 10⁻⁸ = 8 × 10⁷ ...
The temperature dependence of resistivity ρ(T) is influenced by: (a) Number of charge carriers can change with temperature T → In semiconductors and insulators, the number of free charge carriers increases with temperature, significantly affecting resistivity. (b) Time interval between ...
Kirchhoff’s junction rule states that the total current entering a junction equals the total current leaving it, reflecting charge conservation. Since charge cannot accumulate at a junction, the correct answer is (B) conservation of charge and (D) no accumulation of ...
To find the charge, integrate the given current function with respect to time from t = 0 to t = 2. The integral of current over time gives total charge. After solving, the charge is found to be 22 C, ...