An uncharged capacitor is connected to a 21-V battery until it is fully charged, after which it is disconnected from the battery. A slab of paraffin (K= 2.2) is then inserted between the plates. Required:
What will now be the voltage between the plates?

One day, after pulling down your window shade, you notice that sunlight is passing through a pinhole in the shade and making a small patch of light on the far wall. you see that the patch of light seems to be a circular diffraction pattern. it appears that the central maximum is about 1 cm across and you estimate that the distance from the window shade to the wall is about 3 m. what is (a) the average wavelength of sunlight? (b) the diameter of the pinhole?

Using a pedometer, you walk 3000 steps in 20 minutes, so your speed is 150 steps/min. each of your steps is 0.7 m long. what is your speed? 150 steps/min=/s=/h

Abar magnet cut in half will form a total ofpoles.a)fourb)eightc)two