# class 10 Physics mcq questions pdf For UPSC | SSC | Rail | RRB | State PSC P25

Page 25

80059241. Speed of sound is the greatest in :
A
Water
B
Air
C
Glass
D
Glycerine
C
80092242. The term 'Isoneph' indicates the lines of equal
A
cloudiness
B
salinity
C
rainfall
D
pressure
A
80055243. Optic fibers are used in
A
CAT scans
B
X-ray photos
C
Ultrasound scans
D
Endoscopy
D
80098244. Two waves, each of amplitude 1.5 mm and frequency 10 Hz, are traveling in the opposite direction with a speed of 20 mm/s. The distance in mm between adjacent nodes is :
A
1.0
B
1.2
C
L5
D
2.0
A
80072245. The energy stored in a watch spring is
A
kinetic energy
B
potential energy
C
heat energy
D
chemical energy
B
80036246. if the length of a simple pendulum is halved then its period of oscillation is
A
doubled
B
halved increased by a factor
C
increased by a factor √2
D
decreased by a factor √2
D
Correct Answer: D. decreased by a factor √2
80090247. The swing of a spinning cricket ball in the air can be explained on the basis of
A
Sudden change in wind direction.
B
Buoyancy of air.
C
Turbulence caused by wind.
D
Bernoulli's theorem.
C
Correct Answer: C. Turbulence caused by wind.
80028248. Flemings right-hand rule is used to find the direction of the
A
Alternate current
B
Direct current
C
Induced current
D
Actual current
C
80046249. Lambert's law is related to
A
Reflection
B
Refraction
C
Interference
D
Illumination
D
80141250. Which one of the following is used for sunglasses?
A
Pyrex glass
B
Flint glass
C
Crooks glass
D
Crystal glass
C