Academictask provides MCQs of Physics from Basic to Advance, so that you can prepare accordingly. Physics Mcqs section is useful for both students and job seekers i.e MCAT ECAT ETEA test preparation, PPSC Test, FPSC Test
141. When one mirror of a Michelson Interferometer is moved a distance of 0.5 mm we observe 2000 fringes. What will be wavelength of light used ?
A. 5000 nm
142. Wavelength of X-rays falling at glancing angle of 30? on a crystal with atmic spacing 2 x 10-10 for the fist order diffraction is________________?
A. 4 x 10-10 m
B. 2 x 10-10 m
143. In a plane polarized light _________________?
A. vibration in all direction
B. vibration in two mutually perpendicular directions
C. vibration take place in a direction perpendicular to the direction of propagation of light
D. no vibration at all
144. Which one of the following cannot be polarized ?
A. radio waves
B. ultraviolot rays
D. sound waves
145. In monochromatic red light a blue book will probably appear to be_________________?
D. no scientific reasoning available
146. In double slit experiment if one of the two slit is covered then________________?
A. no interference fringes are observed
B. no diffraction fringes are observed
C. no fringes observed
D. interference pattern not disturbed
147. In the shadow of a ball the central portion appears bright that happens due to_________________?
148. Crystals of a material can behave as_________________?
A. Convex lens
C. Diffraction grating
149. Which is not optically active ?
B. tartaric acid
D. sodium chlorate
150. When light incident normally on thin film the path difference depends upon ________________?
A. thickness of the film only
B. nature of the film only
C. angle of incidence only
D. all thickness nature and angle of incidence