Question

Reread the section on error propagation in the lab manual. You want to determine the energy stored in a capacitor for a given voltage. You measure the capacitance C and the applied voltage V and calculate the energy from U = 0.5CV2 Which of the quantities, C or V, should you measure most carefully (with the smallest relative uncertainty) to obtain the most reliable value (smallest relative uncertainty) for U V because its value is usually larger than the value of C. You should measure C and V equally carefully because both enter the equation for U. V because it is squared in the equation. C because you cannot trust the printed value of a capacitance. A stretched string is supported by two bridges a distance L apart. You are driving the string with an inductive coil and find the lowest resonance frequency at 100 Hz. Now you move the bridges a I ittle so that the distance between them is 10% larger than before. The new resonant frequency is the same as it was before. may be larger or smaller: one needs more information to decide is larger than it was before. is smaller than it was before3) You managed to create charged tapes with unequal charges. Tape A carries a positive charge QA = +Q and tape B carries a negative charge that is five times as large, Q_B = -5Q. You measure the Coulomb forces of the tapes on each other and find The Coulomb force on A due to B is five times as large as the Coulomb force on B due to A. The Coulomb force on A due to B is as large as the Coulomb force on B due to A. The Coulomb force on B due to A is five times as large as the Coulomb force on A due to B. The Coulomb force on A due to B is larger, but not five times as large, as the Coulomb force on B due to A. A good way to visualize an electric potential in two dimensions is to think ofa landscape. For each point in the xy plane, the height (z-coordinate) indicates the value of the potential V(x, y). The figure shows four potential landscapes; the colored lines in the figures are lines of constant potential. Which of the figures represents a possible landscape for a positively charged line and a negative point charge in two dimensions

Answer 1