Physics-Objective Related Question Answers
1251. Large transformers, when used for some time, become very hot and are cooled by circulating oil. The heating of the transformer is due to?
both the heating effect of current and hysteresis loss
1252. Nuclear sizes are expressed in a unit named?
Fermi
1253. Light year is a unit of?
distance
1254. Light from the Sun reaches us in nearly?
8 minutes
1255. Stars appears to move from east to west because?
the earth rotates from west to east
1256. Pa(Pascal) is the unit for?
pressure
1257. Planets do not twinkle because?
they are nearer to earth and hence we receive a greater amount of light and; therefore minor variations in the intensity are not noticeable
1258. Metals are good conductors of electricity because?
they contain free electrons
1259. Let a thin capillary tube be replaced with another tube of insufficient length then, we find water?
will not rise
1260. If two bodies of different masses, initially at rest, are acted upon by the same force for the same time, then the both bodies acquire the same?
momentum
1261. Pick out the scalar quantity?
pressure
1262. Rectifiers are used to convert?
Alternating current to Direct current
1263. Sound waves in air are?
longitudinal
1264. Magnetism at the centre of a bar magnet is?
zero
1265. It is more difficult to walk on a sandy road than on a concrete road because?
the friction between sand and feet is less than that between concrete and feet
1266. Find the maximum velocity for the overturn of a car moving on a circular track of radius 100 m. The co-efficient of friction between the road and tyre is 0.2?
14 m/s
1267. Lux is the SI unit of?
intensity of illumination
1268. On a rainy day, small oil films on water show brilliant colours. This is due to?
interference
1269. Point A is at a lower electrical potential than point B. An electron between them on the line joining them will?
move towards B
1270. Materials for rain-proof coats and tents owe their water-proof properties to?
surface tension
1271. RADAR is used for?
detecting and locating the position of objects such as aeroplanes
1272. Sound of frequency below 20 Hz is called?
infrasonic
1273. On a clean glass plate a drop of water spreads to form a thin layer whereas a drop of mercury remains almost spherical because?
cohesion of mercury is greater than its adhesion with glass
1274. Suitable impurities are added to a semiconductor depending on its use. This is done in order to?
increase its electrical conductivity
1275. Stars twinkle because?
the refractive index of the different layers of the earth's atmosphere changes continuously; consequently the position of the image of a start changes with time
© 2002-2017 Omega Education PVT LTD...Privacy | Terms And Conditions
Question ANSWER With Solution