Q1. Two 12-cm-diameter charged rings face each other, 17.0 apart. Both rings are charged to + 40.0. What is the electric field strength at the midpoint between two rings?

Q2. A horizontal desk surface measures 2.06 m x 1.73 m. If Earth's magnetic field has magnitude 0.494 mT and is directed 64.7° below the horizontal, what is the magnetic flux through desk surface?

Q3. A pipe open only at one end has a fundamental frequency of 258 Hz. A second pipe, initially identical to the first pipe, is shortened by cutting off portion of the open end. At this time, when both pipes vibrate at their fundamental frequencies, beat frequency of 12 Hz is heard. How many centimetres were cut off the end of second pipe? The speed of sound is 343 m/s.