مسائل متنوعه في الضوء اتمنى شرحها

[فلوري]

حللت بعض المسائل ولكن لم تعطيني الناتج الصحيح لادري لماذا ؟؟؟؟وهي المسائل الاتية

How much electromagnetic energy is contained in each cubic meter near the Earth’s surface if the intensity of sunlight under clear skies is 1000 W/m2




2. At a distance of 10 km from a radio transmitter, the amplitude of the E-field is 0.20 volts/meter. What is the total power emitted by the radio transmitter?



5. A light ray is partially reflected and partially refracted at a boundary between two media, the upper one having index of refraction n, the lower one having index of refraction n¢, as shown in the figure. The reflected ray is perpendicular to the refracted ray when

[فلوري]

9. If you stand closer to a concave mirror than a distance of one focal length, the image you see is
a. real and inverted. b. real and upright.
c. virtual and inverted. d. virtual and upright.
e. none of the above because you do not get an image


10. Two slits separated by 0.10 mm are illuminated with green light (l = 540 nm). Calculate the distance (in cm) from the central bright-region to the fifth bright band if the screen is 1.0 m away.
a. 2.3 b. 2.5 c. 2.7
d. 2.1 e. 2.0

في هذا السؤال عندما حللته ظهرت لي الاجابة 2.3 ولكن الاجابة الصحيحة هي 2.7 فكيف ؟؟؟؟؟

[فلوري]

اتمنى توضيح الفكرة العامة لهذه المسائل ؟؟؟
The electric fields arriving at a point P from three coherent sources are described by E1 = E0 sin wt, E2 = E0 sin (wt + p/4) and E3 = E0 sin (wt + p/2). Assume the resultant field is represented by Ep = ER sin (wt + a). The amplitude of the resultant wave at P is
a. E0. b. 1.5E0. c. 1.7E0.
d. 2.7E0. e. 2.9E0.



12. Monochromatic light (l = 500 nm) is incident on a soap bubble (n = 1.40). What is the wavelength of the light (in nm) in the bubble film?
a. 255 b. 500 c. 700
d. 357 e. 422

13. In a Newton’s rings apparatus, find the phase difference (in radians) when an air wedge of 500 nm thickness is illuminated with red light (l = 640 nm).
a. 13 b. 11 c. 9

d. 7 e. 3


Determine the number of grating lines necessary to resolve the 589.59 nm and 589.00 nm sodium lines in second order.
a. 999 b. 680 c. 500
d. 340 e. 380

[Lulu Al-Anazy]

شوفي عزيزتي

بالنسبه لاسئله الضوء امس البعض منها حليتها وطلع الناتج صحيح

السؤال رقم (3)


The speed of light changes when it goes from ethyl alcohol (n = 1.361) to carbon tetrachloride (n = 1.461). The ratio of the speed in carbon tetrachloride to the speed in ethyl alcohol, v2/v1, is

الحل:

N1 = 1.361

N2 = 1.461

من القانون الأساسي :

V1/v2 = n2/n1

إذن:

V2/v1 = n1/n2

V2/v1 = 1.361/1.461

= 0.93

[Lulu Al-Anazy]

السؤال رقم 7

A dentist uses a concave mirror (focal length 2 cm) to examine some teeth. If the distance from the object to the mirror is 1 cm, what is the magnification of the tooth?

حملته لك ملف وورد
http://hazemsakeek.com/up/download.php?id=2437

[Lulu Al-Anazy]

السؤالرقم 8


A far-sighted student has a near point of 1.0 m. Calculate the focal length (in cm) of the glasses needed so the near point will be normal
(25 cm)


http://hazemsakeek.com/up/download.php?id=2438

[Lulu Al-Anazy]

السؤال رقم 12

Monochromatic light (l = 500 nm) is incident on a soap bubble (n = 1.40). What is the wavelength of the light (in nm) in the bubble film?

للهواء
n1 = 1.00

λ1 = 500 nm

للصابون
n2 = 1.40
λ2 =???

إذن:

λ1n1 = λ2n2

λ2 = n1λ1 /n2

= 1.00X 500 / 1.40

λ2= 500 / 1.40

λ2 = 357 nm