## Physics (Objective) (Pages :44) <<< Back

• 1261 Let a thin capillary tube be replaced with another tube of insufficient length then, we find water?

Ans : will not rise
• 1262 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?

Ans : momentum
• 1263 Pick out the scalar quantity?

Ans : pressure
• 1264 Rectifiers are used to convert?

Ans : Alternating current to Direct current
• 1265 Sound waves in air are?

Ans : longitudinal
• 1266 Magnetism at the centre of a bar magnet is?

Ans : zero
• 1267 It is more difficult to walk on a sandy road than on a concrete road because?

Ans : the friction between sand and feet is less than that between concrete and feet
• 1268 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?

Ans : 14 m/s
• 1269 Lux is the SI unit of?

Ans : intensity of illumination
• 1270 On a rainy day, small oil films on water show brilliant colours. This is due to?

Ans : interference
• 1271 Point A is at a lower electrical potential than point B. An electron between them on the line joining them will?

Ans : move towards B
• 1272 Materials for rain-proof coats and tents owe their water-proof properties to?

Ans : surface tension
• 1273 RADAR is used for?

Ans : detecting and locating the position of objects such as aeroplanes
• 1274 Sound of frequency below 20 Hz is called?

Ans : infrasonic
• 1275 On a clean glass plate a drop of water spreads to form a thin layer whereas a drop of mercury remains almost spherical because?

Ans : cohesion of mercury is greater than its adhesion with glass
• 1276 Suitable impurities are added to a semiconductor depending on its use. This is done in order to?

Ans : increase its electrical conductivity
• 1277 Stars twinkle because?

Ans : 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
• 1278 It takes much longer to cook food in the hills than in the plains, because?

Ans : in the hills the atmospheric pressure is lower than that in the plains and therefore water boils at a temperature lower than 100oC causing an increase in cooking time
• 1279 Moment of inertia is?

Ans : tensor
• 1280 Inside an aeroplane, flying at a high altitude,?

Ans : normal atmospheric pressure is maintained by the use of air pumps
• 1281 Sound travels with a different speed in media. In what order does the velocity of sound increase in these media?

Ans : Air; water and iron
• 1282 One thousand microns is equal to?

Ans : 10-3m
• 1283 Sound travels at the fastest speed in?

Ans : steel
• 1284 oil raise up the wick in a lamp. The principle involves?

Ans : capillary action phenomenon
• 1285 Superconductors are substances which?

Ans : offer no resistance to the flow of electricity
• 1286 Light travels at the fastest speed in?

Ans : vacuum
• 1287 Railway tracks are banked on curves?

Ans : necessary centripetal force may be obtained from the horizontal component of the weight of the train
• 1288 On a cold day when a room temperature is 15oC, the metallic cap of a pen becomes much colder than its plastic body, though both are at the same temperature of 15oC, because?

Ans : metals are good conductor of heat
• 1289 Sound produced at a point is heard by a person after 5 second, while the same sound is heard by another person after 6 seconds. If the speed of sound is 300 m/s, what could be the maximum and minimum distances between the two persons?

Ans : 3.3 km; 0.30 km
• 1290 Intensity of sound at a point is ____ its distance from the source.?

Ans : inversely proportional to square of

"To love yourself right now, just as you are, is to give yourself heaven. Don't wait until you die. If you wait, you die now. If you love, you live now"

- Alan Cohen