Question

1.

You direct microwaves at a 2 slit filter (Separation between slits is d). What would you expect to see if you place a detector right between the two slits at a distance l away on the outgoing side (l >> d)?

		a minimum signal, as the center is blocked by the filter
		a minimum, because of destructive interference
		a maximum because of constructive interference
		it depends on the spacing of the slits if it is a maximum or minimum
		it depends on the distance from transmitter

2.

Three resistors: 10 ohms, 20 ohms and 40 ohms. If all three are connected in parallel, how much is the equivalent resistor value if replaced with one resistor?  

		70 ohms
		5.7 ohms
		0.175 ohm
		35 ohms

3.

Unpolarized monochromatic light passes through a single polaroid filter, oriented horizontally. It then encounters a second filter that is oriented vertically. Which of the following statements is true of the resulting light?

		The light is entirely blocked
		The emerging light has one half of the incident intensity and is polarized vertically
		The emerging light has the same intensity, but is now polarized at  45o
		The emerging light has one-fourth the incident intensity and is polarized vertically
		The emerging light has one half the incident intensity and is polarized at  45o

4.

Two resistors and a battery are connected in series. What best describes the potentials measured across the two resistors?

		They will be equal, and will add up to the battery voltage
		They will be proportional to the resistance, with the bigger drop across the bigger resistor
		They will be inversely proportional to the resistance, with the bigger drop across the smaller resistor
		You cannot predict without seeing the circuit

5.

If the distance between the object and the screen is 1meter, a thin lens is put in between and moving, when the lens is 30 cm away from the object, a clear image is formed on the screen. How much is the focal length of this thin lens?

		0.048 m
		21 cm
		0.019 m
		52.5 cm

Answer 1