A parallel-plate capacitor filled with air carries a charge q. The battery is disconnected, and a slab of material with dielectric constant k = 2 is inserted between the plates. Which of the following statements is correct?.

How do refracting telescopes magnify a far away image? a. by directing light beams to meet at a focal point b. by absorbing light beams’ wavelengths c. by forcing light beams to change direction d. by measuring light beams’ velocity