Phys1320 Pre lab Y3
1. There are two slits at A and C in the diagram. Light passes through the slits from the left.
One of the light rays (AD or CD) must travel farther than the other to reach the screen on
the right.
Which line represents the extra distance that must be traveled:
AB, AC, AD, AE, BC, CD, CE, or DE?
ANSWER: AE
2. [2pt]
Images of a slit pair and a transparent ruler, with centimeter graduations, are projected
onto a distant screen. If a length of 2 cm on the ruler is magnified to a length of 39.1 cm
on the screen, and the separation of the slit centers is magnified to 3.21 cm, what is the
actual separation of the slits? (Note: To the eye, the slits appear to be 1 mm - 3 mm
apart.)
ANSWER: 1.64 mm
magnification = 39.1cm/2cm = 19.55 cm
Magnification = magnified slit separation/actual slit separation
=> actual slit separation = 3.21/19.55 = 0.164 cm = 1.64 mm
3. [4pt]
In a two-slit interference experiment, with a light source of unknown wavelength, the
following data are measured:
1. There are two slits at A and C in the diagram. Light passes through the slits from the left.
One of the light rays (AD or CD) must travel farther than the other to reach the screen on
the right.
Which line represents the extra distance that must be traveled:
AB, AC, AD, AE, BC, CD, CE, or DE?
ANSWER: AE
2. [2pt]
Images of a slit pair and a transparent ruler, with centimeter graduations, are projected
onto a distant screen. If a length of 2 cm on the ruler is magnified to a length of 39.1 cm
on the screen, and the separation of the slit centers is magnified to 3.21 cm, what is the
actual separation of the slits? (Note: To the eye, the slits appear to be 1 mm - 3 mm
apart.)
ANSWER: 1.64 mm
magnification = 39.1cm/2cm = 19.55 cm
Magnification = magnified slit separation/actual slit separation
=> actual slit separation = 3.21/19.55 = 0.164 cm = 1.64 mm
3. [4pt]
In a two-slit interference experiment, with a light source of unknown wavelength, the
following data are measured:
