Author Question: A 1.50-H inductor is connected in series with a 200- resistor through an ideal 15.0-V dc power ... (Read 59 times)

V@ndy87 · **on:** Jul 29, 2018

A 1.50-H inductor is connected in series with a 200- resistor through an ideal 15.0-V dc power supply and an open switch. How much energy is contained in the inductor 20.0 ms after closing the switch?

A) 5.48 mJ B) 0.910 mJ C) 7.31 mJ D) 3.65 mJ E) 1.83 mJ

Question 2

An amateur astronomer grinds a double convex lens whose surfaces have radii of curvature of magnitudes 40 cm and 60 cm. The glass has an index of refraction of 1.54. What is the focal length of this lens when used in the night air?

A) 220 cm B) 43 cm C) 130 cm D) 89 cm E) 44 cm