Question

PITCR SUULIS . NUUJIU J'S- AU CU 1.) Two electromagnetic waves of the same frequency, each having average intensity of 2 W/m. overlap and interfere in space. Which of the following is a possible intensity of the wave formed by the superposition of these two waves? A) 4 W/m B) 2 W/m2 C) 1 W/m D) O W/m E) Any of A, B, C, or D is a possible intensity of the superposed wave 2.) A linearly polarized electromagnetic plane wave propagates in the +x direction through vacuum. The polarization axis of this wave: A) must be parallel to the x-axis B) must be parallel to the y-axis C) must be parallel to the z-axis D) can be along any line in the yz-plane E) can be along any line in the xz-plane 3.) A dentist puts a mirror in your mouth to look at a tooth. The image of the tooth as reflected by the mirror is larger than the actual tooth (the image is magnified). From this, you can determine that the shape of the mirror must be: A) flat B) concave (converging) C) convex (diverging) D) either concave or convex E) either flat or convex 4.) To take a photograph of a tree, a lens is used to project an image of the tree onto a sheet of film. Compared to the actual tree, the image on the film appears: A) upside down (inverted) B) rotated clockwise by 90° C ) right-side up (upright) D) rotated counterclockwise by 90° E) Trick question! The image is virtual and so can't be projected on the film. 5.) In a microscope, light from the objective lens shines with a constant intensity onto a circular aperture with open diameter of 2.0 mm, and a light power of 0.10 W is transmitted through the aperture to the eyepiece. If you increase the aperture's open diameter to 6.0 mm, the light power transmitted through the aperture will be: A) 0.033 W B) 0.90 W C) 0.17 W D ) 0.30 W E) 0.011 W

Answer 1

ans. 1) Recall Isotal I + I2 + 2/5, Iz Coso here I = I 2 = 2 W/m2 1Ft = I +1 +2 I Cose = 21(1+(050) = 411 troso) Imax = 800/m? Imin=0 Sook It (8 hence (E) is correct 2) Polarization axis should be fr to x-axis, so it would be along y or z-axi's So it in y-z plane. (D) is correct option 3) magnifier uses convex lense. 4) The image is virtual and can't be projected on filmo 5) I-f. 0.1 So P = Poreen through 3mm redius apertine (141032 - 0.1 x 119xió) = 0.9 watt And, Ans. 166)