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# Physical Science

296)Which of the has equal periods od rotation and revolution?
Mercury Venus
Moon Uranus

297)Weight of a person can be zero when
1. he is falling freely
2. he is orbiting in a satellite
3. he is in an aeroplane flying at a high altitude
4. he is having ride in a gas balloon
1 and 3 1 and 2
1, 2 and 3 all of them

298)Mountain roads wind up gradually and do not go up straight, because
winding roads offer more friction making driving easier it is easier to construct winding roads
chances of accident is less in winding roads on winding roads less force is required to overcome the gravity

299)For the same weight and same fuel supply, a multistage rocket is preferred over a single stage rocket, because
it is easier to assemble a multistage rocket it is cheaper to build a multistage rocket
final velocity acheived in a multistage rocket is higher final velocity acheived in a multistage rocket is lower

300)Consider the metals
1. Platinum
2. Gold
3. Copper
Their correct order in the ascending order of density is
1, 2, 3, 4 2, 3, 4, 1
3, 4, 2, 1 4, 3, 2, 1

301)The earth and the moon are about the same distance from the sun, yet on the average the earth is much warmer than the moon. Why?
The moon has almost no atmosphere The surface of the moon is darker
Nights on the moon are much longer The moon is much smaller than the earth

302)There is no Doppler effect for sound when
the source produces a sound of very high frequency the source of sound recedes from the observer
the source of sound approaches the observer the source of sound moves at right angle to the line joining the source and the observer

303)Match the following
```1. Force                            a. watt
2. Energy                           b. pascal
3. Power                            c. newton
4. Pressure                         d. Joule
```
1-a, 2-b, 3-c, 4-d 1-c, 2-a, 3-d, 4-b
1-c, 2-d, 3-a, 4-b 1-b, 2-a, 3-d, 4-c

304)Consider the following electromagnetic waves
1. Ultraviolet
2. Microwaves
3. X-rays
Their correct arrangement in the ascending order of wavelength is
1, 2, 3, 4 3, 1, 2, 4
4, 3, 2, 1 3, 2, 4, 1

305)A star with a mass of less than 1.4 solar masses will probably end its life as a
black hole pulsar
white dwarf neutron star

306)Match the following
```A. Mars                              1. Titan
B. Saturn                            2. Miranda
C. Uranus                            3. Phobos
D. Jupiter                           4. Ganymede
```
A-3, B-1, C-2, D-4 A-3, B-2, C-1, D-4
A-4, B-1, C-2, D-3 A-2, B-1, C-3, D-4

307)Rocks of which planet are likely to float on water?
Mars Saturn
Jupiter Venus

308)Among the moons of the planets, the largest is
Callisto of Jupiter Rhea of Sarurn
Ganymede of Jupiter Titan of Saturn

309)Which of the Jupiter's moons are larger than the planet Mercury?
1. IO
2. Ganymede
3. Europa
4. Callisto
1 and 2 2 and 3
3 and 4 2 and 4