Sample Paper Astronomy Jl

INDIAN ASSOCIATION OF PHYSICS TEACHERS NATIONAL STANDARD EXAMINATION IN ASTRONOMY ASTRONOMY Sample paper – JUNIOR LEVEL

Approximate Values of some important constants are: Mass of Earth ~ 6 x 10 24 kg Radius of Earth ~ 6,000 km 1 AU ~ 1.5 x 10 11 meter 1 year ~ 3 x 10 7 sec Charge of electron ~ 1.6 x 10 -19 C Avogadro Constant ~ 6.02 x 10 26 /kmole Gravitational Constant ~ 6.7 x 10 -11 (MKS) Boltzmann’s Constant ~ 1.4 x 10 -33 J/K g = 10 m/s 2

Astronomy Sr.

Mass of Sun ~ 2 x 10 30 kg Radius of Sun ~ 7 x 10 8 Meter 1 parsec ~ 3.26 light years Speed of light ~ 3 x 10 8 m/s Mass of electron ~ 9 x 10 -31 kg Mass of proton ~ 1.7 x 10 -27 kg Planck Constant ~ 7 x 10 -34 Js Stefan’s Constant ~ 6 x 10 -8J/s/m2

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ATTEMPT ALL QUESTIONS Total Marks: 150

Duration: 90 Minutes

Section I There are 30 questions, each having one correct option. Each correct answer carries 3 marks, while each wrong answer has a penalty of

1

mark.

1) A cycle tends to slip on a wet road but not on a dry road because a) b) c) d)

Dry road has lower friction Shining surface of of a wet road reflects the bicycle The reaction exerted by a tar surface is stronger Water acts as a lubricant

2) The length of a year is 365.24 days but I assume it to be 365.00 days. What is the percentage error in my calculation? a) b) c) d)

0.07 years 0.14% 0.24 days 0.07%

3) What is the angular speed of a second’s hand of a watch? a) b) c) d)

1 radian/s 2 π radians/s ~ 0.1 radians/minute radians/minut e 2 π radians/ minute

4) Assume that an object is 10 light years away from you. Calculate its distance in km. a) b) c) d)

1 x 102 9 x 1010 9 x 1013 9 x 1016

5) If there were no atmosphere, the duration of day light on the earth will a) b) c) d)

decrease increase remain same will decrease or increase depending on latitude

6) A telescope with a magnification of 100 X has an eyepiece of focal length 32 mm. It is placed in Allahabad. What is the farthest object you can see with this telescope? a) b) c) d)

Top of Mount Everest Pluto Edge of Milky way Andromeda Galaxy

Astronomy Sr.

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7) y = log(log(10)). What is the value of y? a) b) c) d)

–1 0 1 10

8) Which of the following stars is not on the Zodiacal Belt? a) b) c) d)

Spica Pollux Aldebaran Sirius

9) Which of the following constellations is circumpolar from Delhi? a) b) c) d)

Hydra Leo Minor Ursa Minor Libra

10) A thick mirror forms multiple images. Which image will be the brightest? a) b) c) d)

1st 2nd 3rd last

11) A microphone does the following a) b) c) d)

It converts sound energy into electrical energy It amplifies the sound It converts electrical energy into sound energy It converts sound energy into mechanical energy

12) A blue coloured torch is viewed through a red filter. What will you see? a) b) c) d)

The torch light will appear blue The torch light will appear red The torch light will appear white No torch light will be seen

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13) A crab is moving towards the mirror (see figure below) at 2 cm/s making an angle of 60 0 with the mirror. .At what rate will the image of the crab move towards the crab

a) b) c) d)

1 cm/s \/ 3 2 cm/s 4 cm/s

14) In the figure below black boxes indicate resistances. How much energy is dissipated in the circuit below in 1 minute?

a) 50 J

b) 60 J

c) 360 J

d) 1800 J

15) If A and B are two sets with 3 and 6 elements respectively, what is the minimum numbers present in the set A U B ? a) b) c) d)

3 6 9 18

16) A person of mass 50 kg drinks 1 litre of water. What is his approximate increase in mass? a) b) c) d)

0.02 kg 0.2 kg 1 kg 2 kg

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17) Three resistances of value 1, 2 and 5 have to be connected in such a way that all the resistances are used once. Which value of resistance cannot be obtained? a) b) c) d)

17/3 17/4 17/6 17/7

18) A plane mirror starts going away from you at a speed of 20 cm/s from a distance of 50 cm/s from you. You can see your image in it. At the 4 th second the distance of your image from you will be a) b) c) d)

130 cm 260 cm 180 cm 360 cm

19) The refractive index of water is 1.33. The speed of of light in water is 8 a) 1.33 x 10 m/s b) 2.25 x 108 m/s c) 3 x 108 m/s d) 4 x 108 m/s

20) If a/ ( b+c) = b / ( a + c) = c / (a +b) and a+b+c is a) b) c) d)

≠

0, then each ratio is

1 1/2 0 -1

21) Bhargava Ram is facing two equidistant mirrors which are at 45 0 to each other. Assuming he is not drunk, how many images will he see of himself? a) 2 b) 3 c) 7 d) 8 22) Two mirrors are placed parallel to each other on a sea-saw. A beam incident in an almost vertical plane, on the first mirror is reflected to be incident on the second and then is further reflected to form a spot on the wall at some distance away. If the sea-saw is turned through an angle θ, through what angle the reflected beam will turn? a) zero b) θ c) 2 θ d) 4 θ 23) A star A is green in colour while star B is red in colour. If the two stars collide to form a single star what will be its colour? a) b) c) d)

red orange yellow blue Astronomy Sr.

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24) Which of the following stars you will not surely observe tonight? a) b) c) d)

Sirius Regulus Polaris Antares

25) For the regular pentagon ABCDEA, L CAE = ? a) b) c) d)

540 600 660 720

26) Astronomers prefer larger telescope because a) b) c) d)

it gives brighter image it gives larger image it gives larger field of view it is sensitive to wider range of wavelengths

27) Parag arrives at Pimpari railway station from office everyday at 6:00 pm. Where Prajakta picks him up in the car to take him home. One day he arrives at Pimpari one hour early and starts walking towards home. On the way he meets Prajakta and they return home together in the car. If they arrive home 10 minutes earlier then what is the ratio of Parag’s walking speed to the Prajakta’s driving speed? a) b) c) d)

1/11 1/10 1/60 data is not sufficient

28) If the plane in which the moon orbits the earth were same as the plane in which the earth orbits the sun, how often in a year would we observe the full moon? a) everyday b) 12 times c) 25 times d) never 29) A wooden cube ( density 0.06 g/cc) just dips inside the water if pressed with a force of 10N. What must be the side of the cube? (Assume g = 10 m/s 2) a) b) c) d)

1/ 401/3 m 1/ 4001/3 m 1/40001/3 m 0.5 m

30) A boat can carry at the most three persons at a time. If 9 persons have to cross the river using the boat, how many minimum number of times it must cross the river? a) 3 b) 4 c) 5 d) 7  ________________________________________________________________________________  Astronomy Sr.

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Section II There are 10 questions with 6 marks each. Each question may have more than one correct alternative. If all the correct alternatives are marked, only then 6 marks will be allotted. Else 0 marks.  ________________________________________________________________________________  1) A body A of density a) b) c) d)

ρ

is immersed in a liquid B of density ρ’. Then,

apparent loss in weight of A is zero if ρ < ρ’ A can remain in any position inside B if ρ = ρ’ A apparently loses all its weight if ρ < ρ’ The fraction of the volume of of A below B is ρ / ρ’ if ρ < ρ’

2) A group of parallel rays is incident on a lens. The rays after refraction would converge or diverge depends upon a) b) c) d)

the size of the lens the radii of curvature of the two surfaces the refractive refracti ve index of the surrounding medium the refractive index of the material of the lens

3) The planet/s that does/do NOT have natural satellite is/are a) b) c) d)

Mars Mercury Jupiter Venus

4) The time rate of conduction of heat through a given slab of a material depends upon a) temperature of the surrounding b) area of cross section c) thickness of the slab d) the temperature difference across the slab 5) Two plane mirrors are placed in such a manner that a light ray incident on the first gets reflected towards the other and finally gets reflected along a line parallel to the initial ray. Therefore, the angle between the two mirrors can be a) b) c) d)

450 900 00 600

6) A light bulb is said to be only 10 % efficient. This means a) only 10 % of the electrical energy is consumed b) 90 % energy goes as heat c) only 10 % energy is converted to light d)as compared to tube light only 10 % light is given

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7) The Sun appears oval shaped when it is at the horizon, it is due to a) More dispersion of light through atmosphere from lower edge of Sun than from its upper edge b) More diffraction of light through atmosphere from lower edge of of Sun than from its upper edge c) More refraction of light through atmosphere from lower edge of of Sun than from its upper edge d) More interference of light through atmosphere from lower edge of of Sun than from its upper edge. 8) Which of the following can produce a virtual image? a) Plane mirror b) Convex mirror c) Concave mirror d) Prism 9) Lightening arrester is pointed because a) b) c) d)

induced charge density is highest at pointed surface direction of electric electric field is well defined lightening is always a thin streak it provides minimum resistance to wind

10) World’s best observatories are situated at mountaintops because a) it is closer to the sun b) clouds are less c) atmosphere is thin d) it is cool and comfortable there

End of Junior Level Section II

Astronomy Sr.

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