Question

1. In the figure, the neutral density filter is set at 100% transmittance on the side of source 2, The polarizers set at an angle of zero is placed between source 1 and the photometer. How does the distance of the first source (from the photometer) r1 compare to the distance of the second source r2 if the two sides of the photometer have the same brightness?

a. r2 = 0.6 r1

b. r2 = 0.8 r1

c. r2 = 0.4 r1

d. r2 = 0.5 r1

e. r2 = 0.7 r1

2. A small light source radiates light uniformly in all directions. The intensity at point 1, a distance of 1.0 m from the source is found to be twice the intensity at another point 2. How far is point 2 from the source?

In the figure, the neutral density filter is set at 100% transmittance on the side of source 2, The polarizers set at an angle of zero is placed between source 1 and the photometer. How does the distance of the first source (from the photometer) rį compare to the distance of the second source r2 if the two sides of the photometer have the same brightness? polarizers neutral density filter photometer light source 2 light source 1 r2 r2 = 0.8 ri o r2 = 0.7 r1 r2 = 0.6 r1 r2 = 0.5 r1 r2 = 0.4 ri

a. 4.0 m

b. 0.7 m

c. 2.8 m

d. 2.0 m

e. 1.4 m

3. A proton is projected downward with a speed of 3 x 10⁷ m/s in a region where the Earth's magnetic field is 5 x 10^-5 T northward. What is the magnetic force exerted by the Earth on the proton?

a. 4.2 x 10^-16 N, eastward

b. None of the choices is correct

c.  4.2 x 10^-16 N, westward

d. 2.4 x 10^-16 N, westward

e. 2.4 x 10^-16 N, eastward

Answer 1

is reduced 1) Energy (Intensity) by a polarizer By a factor of is not reducing anything 6 density filler it is set at 100% transmitance given to us in that intensity is same at photometer Intensity due to #1 Intensity due to #2 out pleotermeter = 1 I e at plotometer - To ho I To 31 2 2 28,2 ni 0.7 82 2) In Intensity Citshould be leither above 61 40 12 82=1.48 at point l (I)= Intensity at point 2 (F} 4T 82 given I z 2 Iz 47 4082 82= re 104m 2

Date: - 3) V= 3x107 m/s (down) B = 5x10-5T North AB force= q (VXB TAL 1.6810-19 x 3x107x5x105 Cinto the page) 2.4x10-16 N direction - kx I i (East) 72 (k) Hores AN Wk DE south Ans 2.4 x 10-6 N Eastward