Blue light (wavelength 450 nm) and gold light (wavelength 580 nm) are both shone
ID: 1555690 • Letter: B
Question
Blue light (wavelength 450 nm) and gold light (wavelength 580 nm) are both shone on a single slit. If the difference in position between the first blue minimum and the first gold minimum is 1.3 mm on a screen that is 1.5 m away, what is the width of the slit? 0.67 mm 0.52 mm 0.23 mm 0.15 mm None of the above is correct. Consider a converging lens mounted on a table. If an insect lands 15 cm directly in front of the lens, where would you have to place a screen to see the insect? The lens has a magnification of 2. 23 cm on the insect's side of the lens 23 NOT on the insect's side of the lens 30 cm on the insect's side of the lens 30 cm, NOT on the insect's side of the lens 15 cm on the insect's side of the lens Which of the lenses in the diagram below is the converging lens with the smaller focal length? ____ All of the above When viewing the world around you, the cornea in your eye acts as a single Diverging lens. Converging lens. Convex mirror. Concave mirror. None of the above is correct.Explanation / Answer
10)
For single slit we use equation
dsin=m ………………..for minimum
d*ygold/D= gold -------------(1)
d*yblue/D= blue -------------(2)
(1)– (2),
d*ygold/D - d*yblue/D = gold - blue
d/D(ygold - yblue) = gold - blue
d = (gold - blue)D/( ygold - yblue)
d= [(580*10^-9-450*10^-9)*1.5]/( 1.3*10^-3)
d= 1.5*10^-4
11)
m= -di/do = -2
di=2*do=2*15cm = 30cm
Means di is positive value. Which suggest di is opposite side of the insect.
Thus correct answer is d) 30cm, NOT on the insect side of the lens
12)
Lens ‘B’ has smaller converging focal length
13)
Cornea acts as converging lens