WorksheetsMCQ physics practical 9
Total questions: 81
Worksheet time: 41mins
188. To get a good quality image when using anoptical microscope, the object must be placed at a distance:
a. Less than the focal distance of the objective
b. Greater than one focal distance but less than double the focal distance of the objective
c. Exactly at the focal distance
189. The magnification of the objective is:
a. Linear
b. Angular
c. Both, linear and angular
190. The optimal combination of objective and ocular (eye piece) in an optical microscope
requires the following relationship between the respective magnification coefficients (W):
a. Wocl = Wobj
b. Wocl>Wobj
c. Wocl<Wobj
191. The image formed from the objective appears before the eyepiece (ocular) at a distance:
a. Less than the focal distance of the ocular
b. Greater than the focal distance of the ocular, but less than the double focal distance of the ocular
c. Exactly at the focal distance of the ocular
192. What is the highest resolution of standard optical microscopes (set by the diffraction limit)?
a. 20 μm
b. 2 μm
c. 0.2 μm
193. The final image formed by a compound optical microscope is:
a. Magnified, inverted, real
b. Magnified, inverted, virtual
Magnified, inverted, real
194. Infrared rays are:
a. Electromagnetic radiation
b. Electron beam
c. Low frequency sound waves
195. Which of the following phenomena is applied in optical microscopes?
a. Compton scattering
b. Refraction
c. Stimulated emission
196. Numerical aperture (NA) of optical microscopes has influence on:
Magnification
Half life
Resolution
97. How can a CCD camera capture the virtual image formed by the ocular of a standard microscope?
a. By converting the image into real by using an ocular with a shorter-than-usual focal length
b. By converting the image into real by using an objective with shorter-than-usual focal length
c. By magnifying the image past the ocular, and turning it into real
198. Which of the following optical elements of the light microscope is limiting for the maximal resolution?
a. Objective
b. Ocular (eyepiece)
c. Condenser
199. Which of the following statements regarding numerical aperture (NA) of an optical microscope is FALSE?
a. Depends on the wavelength if incident light
b. Characterizes objective’s capacity to gather light
c. Depends on the refraction index of the immersion
200. How is optical (microscope) resolution defined?
a. The smallest resolvable distance between two distinguishable objects
b. The size of the smallest pixel
c. The inverse of the minimal distance between two distinguishable objects
201. Which of the following is the mathematical definition of optical power of a lens (dioptre)?
a. P = n/f
b. P = 1/n Where: f – focal length; n-index of refraction
c. P = 1/f
202. Total internal reflection occurs when light travels from:
a. Material with higher optical density into material with lower optical density
b. Material with lower optical density into material with higher optical density
c. Materials with identical optical densities
203. The resolution of optical microscopes is inversely proportional to:
a. The size of the tubus
b. The numerical aperture NA
c. The magnification of the objective
204. Illumination with polarized light is used for:
a. Optically active (birefringent) materials
b. Transparent samples
c. Stained samples
205. Which of the images bellow shows the correct path of a light beam passing through a lens?
image a
image b
image c
206. Cedar oil is used for:
a. Dark field illumination
b. Bright field illumination
c. Immersion microscopy
207. The Condenser is an integral part of the optical microscope, that
a. Focus light from the light source into the sample
b. Compresses the image onto the objective
c. Focuses the image onto the eyepiece
208. The term “monochromatic“ refers to:
a. Electromagnetic waves with the same frequency
b. Electromagnetic waves with different frequency
c. Electromagnetic waves that all move in the same direction
209. If the angle of incidence of beam of light is 30 degrees (from the normal), then the reflected beam is at:
a. 0 degrees
b. 30 degrees
c. 60 degrees
210. Optical power of a lens is defined as:
a. Proportional to the focal length of the lens
b. Inversely proportional to the focal length
c. Equal to the focal length of the lens
211. When beam of light crosses between two materials of different optical density, it will change direction. This phenomenon is called:
a. Refraction
b. Reflection
c. Scattering
212. The refraction angle is defined as:
a. The angle between the refracted beam and the boundary surface b. The angle between the incident and refracted beams
a. The angle between the refracted beam and the boundary surface b. The angle between the incident and refracted beams
c. The angle between the refracted beam and the normal (perpendicular) to the surface
213. If light passes through a Convex lens, the image will be real, inverted, and magnified when:
a. The object is placed at distance greater than double the focal length
b. The object is located between the focal distance and the lens
c. The object is placed between the focal distance and double the focal distance
214. Light travels faster in materials with:
a. Greater optical density
b. Lesser optical density
c. Light always travels with constant speed c
215. Double concave lens will form a virtual, erect, and reduced image when:
a. The object is placed at double the focal distance
b. The object is between the focal distance and the lens
c. Concave lens do not generate virtual images
216. Visible light is:
a. Electromagnetic waves with frequency from 20 Hz to 20,000 Hz
b. Electromagnetic radiation with wavelengths between 380 – 760 nm
c. Beam of electrons and neutrinos
217. Pick the correct statement about light
a. Neutrinos travel with the speed of light
b. Light propagates as a mechanical wave
:c. Light is absorbed in energy quanta
218. The energy of light quanta is given by the following equation:
Where: h is Plank constant; f is frequency of light; λ is wavelength of c. E = h·λ light; c is the speed of light.
a. E = h·f
b. E = m·c2
c. E = h·λ light;
219. Which of the following colors is not considered primary (according to the RGB system)?
a. Blue
b. Brown
c. Red
220. Which properties of light CANNOT be explained with the electromagnetic wave formalism?
a. Reflection
b. Atomic absorption and emission
c. Diffraction
221. The speed of light in vacuum is universal constant and the upper physical speed limit. Is it possible for the speed of light to change and how?
a. It is always the same
b. It depends on the electric and magnetic permeability of the propagating medium
c. It depends on the energy of the photons
222. In which of the following mediums does light travel the fastest?
a. In air
b. Inside a diamond
c. In vacuum
224. Where in the electromagnetic spectrum can important boundaries be drawn with regard to human physiology?
a. For visible light (380 nm- 760 nm) because of the human eye, and at 10 nm (the boundary of ionizing radiation between UV and x-rays)
b. There are no important boundaries that can be drawn in the electromagnetic spectrum
c. The boundary of gamma rays
225. What is the color of Sunlight (by definition)?
a. White
b. Yellow
c. Red
226. What is the minimal difference in wavelength ∆λ between two light waves so that they appear as different colors to the human eye (i.e. the wavelength resolution of the eye)?
a. ∆λ ≥ 2 nm
b. ∆λ < 2 nm
c. ∆λ < 2 THz
227. Which of the following statements, related to geometric optics, is FALSE?
a. In optically linear mediums, light propagates as straight rays
b. In optically linear mediums light rays do not interact with each other and with the propagating medium
c. When crossing boundaries between two mediums the speed of light does not change
228. Frequency of visible light is greater than the frequency of:
a. Infrared rays
b. Ultraviolet rays
c. X-rays
229. A common medical application of the effect “total internal reflection” is in the:
a. Endoscope
b. Diopter meter
c. Laser
230. The so called Sun Protection Factor (SPF) of common sunscreens refers to the range of protection from (ultraviolet rays)
a. UV A
: b. UV B
c. UV C
231. For the best image quality with optical microscope, the object must be placed at distance:
a. Less than the focal distance of the objective
b. Between the focal distance and double the focal distance of the objective
c. Exactly at the focal distance of the objective
232. Which of the following wavelengths from the electromagnetic spectrum CANNOT be perceived by the human eye?
a. λ = 500 nm
b. λ = 1000 nm
c. λ = 620 nm
233. Which of the following wavelengths form the electromagnetic spectrum CAN be perceived by the human eye?
a. λ = 500 nm
b. λ = 200 nm
c. λ = 1020 nm
234. What type of surface causes a “diffuse reflection”?
a. Mirror surface
b. Irregular surface, where the size of the irregularities is in the order of the wavelength of incident light
c. Where reflected rays are parallel
235. Ultraviolet rays have shorter wavelengths than:
a. Visible light
b. X-rays
c. Gamma rays
236. What is the advantage of polarization optical microscopes compared to conventional optical microscopes?
a. Greater resolution
b. Visualization of optically active structures
c. Direct visualization
237. In a polarized beam of light, the electric field vector E oscillates:
a. In all directions
b. In one direction
c. In two mutually perpendicular directions
238. Endoscopes in medical practice are used for the study of:
a. The brain
b. The skin
c. Hollow organs
239. Which of the following parts are found in polarization microscopes but not in conventional microscopes?
a. Polarizer and Analyzer
b. Condenser and Prodenser
c. Vacuum chamber
240. Ultraviolet rays that cause erythemic reaction (redness) are in the wavelength range of
: a. 400 nm – 315 nm (UVA)
b. 315 nm – 280 nm (UVB)
c. 280 nm – 100 nm (UVC)
241. The image formed by the eyepiece (ocular) is:
a. Real
b. Virtual
c. Virtual and reduced
242. Infrared rays are an type of electromagnetic radiation with wavelength range:
a. 760 nm – 1000,000 nm (1mm)
b. Below 380 nm
c. 2.5 μm – 50μm
243. Typical effect of the infrared radiation is:
a. Ionization of the atoms of the substance
b. Increase of the temperature
c. Excitation of electronic energy states
244. Infrared photons:
a. Have lower energy than visible light
b. Have higher energy than UV photons
c. Do not move at the speed of light
245. Total internal reflection is when:
a. The angle of incidence is 90 degrees
b. The angle of refraction is 90 degrees
c. When light crosses between to mediums
246. Material is called “optically dense” when:
a. It has a high index of refraction
b. It has a low index of refraction
c. It is not transparent
247. What can be said about two light sources, propagating in the same medium, with wavelengths of 630 nm and 450 nm?
a. The two light beams are coherent
b. The light beams have different frequency
c. The light beams have different speeds
248. Which of the following has the greatest effect on the angle of refraction?
a. The optical density of the incident medium
b. The optical density of the refracting medium
c. The ratio of the respective indices of refraction of the two materials
249. The index of refraction (n) of particular material depend on:
a. The angle of incidence of light
b. The propagation speed of light in the particular material
c. The angle of reflection
250. Microwaves are part of the electromagnetic spectrum between the infrared and:
a. Ultraviolet rays
b. Gamma rays
c. Radiowaves
251. Electromagnetic waves listed in the order of increasing frequency:
a. Microwaves, ultraviolet, visible, infrared
b. Visible, ultraviolet, infrared, microwave
c. Microwaves, infrared, visible, ultraviolet
252. Electromagnetic waves listed in the order of increasing energy:
a. Microwaves, infrared, visible, ultraviolet
b. Visible, ultraviolet, infrared, microwave
c. Microwaves, ultraviolet, visible, infrared
253. When a light ray enters material with greater optical density, its speed will:
a. Increase
b. Decrease
c. Remain the same
254. Due to climate and atmospheric changes the intensity at Earth surface of this type of radiation is increased:
a. Ultraviolet rays
b. X-rays
c. Radiowaves
255. When monochromatic light passes from glass into air:
a. The frequency increases
b. The speed increases
c. The frequency decreases
256. The dependence of the angle of refraction of light in a transparent material on the frequency of the incident light is called:
a. Dispersion
b. Diffraction
c. Polarization
257. How does wavelength of blue light compare to wavelength of red light?
a. Red light has a longer wavelengt
h b. Blue light has a longer wavelength
c. They have the same wavelength but different frequency
258. Electromagnetic wave with a wavelength of λ = 0.555 μm is within the:
a. Visible spectrum
b. Infrared spectrum
c. Microwave
259. Electromagnetic waves and mechanical waves share the following common properties:
a. Transverse and longitudinal modes of propagation
b. Propagation in vacuum
c. Transfer energy
260. When light crosses from air into water, the angle of incidence is:
a. Greater than the angle of refraction
b. Lesser than the angle of refraction
c. Identical to the angle of refraction
261. When white light passes through a prism, different colors (wavelengths) refract differently. Which color refracts the least? .
a. Red
b. White
c. Violet
262. When light travels from one material into another its speed (c=f·λ) changes. What else changes?
a. Its frequency (f)
b. Its wavelength (λ)
c. Its color
263. The energy of the light packets (photons) is related to their wave property frequency (f) by the following equation:
a. E = h·f (energy is proportional to frequency)
b. E= h/f (energy is inversely proportional to frequency)
c. E = h·f2 (energy is proportional to the square of the frequency)
264. Light travels the fastest in:
a. Water
b. Air
c. Vacuum
265. When light travels from air into water, which of its properties is conserved (unchanged)?
a. Speed
b. Energy
c. Direction of propagation
266. When frequency of electromagnetic wave is increased, its speed:
a. Increases
b. Stays the same
c. Decreases
267. Light beam with a longer wavelength will have
: a. More energy than light beam with a shorter wavelength
b. Less energy than light beam with a shorter wavelength
c. Higher frequency than light beam with a shorter wavelength
268. Match given wavelengths with the appropriate type of electromagnetic radiation:
a. 100 μm-----------> 1. IR rays
b. 55 nm ----------->2. UV rays
c. 700 nm-----------> 3.Visible
d. 0.01 nm----------> 4. X-rays
223. Regarding to the electromagnetic spectrum, which electromagnetic waves correspond to the highest and lowest energies?
a. Gamma rays correspond to the highest energy, and infrared to the lowest
b. X-rays correspond to the highest energy, and microwaves to the lowest
c. Gamma rays have the highest energy, and radio waves have the lowest
