Physics MCQS

991. The SI unit of work is?
A. Watt
B. Newton
C. Newton second
D. Joule

992. The value of the escape velocity for the earth is approximately equal to?
A. 11 m/s
B. 11 km/h
C. 11 km/min
D. 11 km/s

993. The escape velocity for the earth depends upon?
A. The radius of the earth
B. The mass of the body
C. Mass of the earth
D. Both A & C

994. Mathematically, work can be defined as?
A. W=Fdsinθ
B. W=Fvsinθ
C. W=F.d
D. None of the above

994. The appearance of color in thin films is due to
A. Diffraction
B. Dispersion
C. Interference
D. Polarization

995. The blue color of the sky is due to
A. Diffraction
B. Reflection
D. Polarization
D. Scattering

996. A light ray traveling from a rarer to a denser medium suffers a phase change of
A. 60°
B. 90°
C. 180°
D. 45°

997. When one mirror of a Michelson Interferometer has moved a distance of 0.5 mm we observe 2000 fringes. What will be the wavelength of light used?
A. 5000 nm
B. 5000Å
C. 500m
D. 2000um

998. Diffraction effect is
A. More for a round edge
B. Less for a round edge
C. More for a sharp edge
D. Less for a sharp edge

999. The wavelength of X-rays is of the order of
A. 10 microns
B. 1 angstrom
C. 1 cm
D. 1 m

1000. The wavelength of X-rays falling at a glancing angle of 30° on a crystal with atomic spacing 2 x 10-10 for the first-order diffraction is
A. 4 x 10-10 m
B. 2 x 10-10 m
C. 0.02×10-10m
D. 20×10-10m