In air a concave mirror has a focal length of 30. cm. Under water that same mirror would have ________ focal length.
A) a larger
B) the same
C) a smaller
Question 2
A parallel plate capacitor with plate separation of 4.0 cm has a plate area of 4.0 10-2 . What is the capacitance of this capacitor with air between these plates?
A) 8.9 10-11 F
B) 8.9 10-12 F
C) 8.9 10-13 F
D) 8.9 10-14 F
E) 8.9 10-15 F