MOST IMPORTANT MCQs ON KEPLER'S LAWS OF PLANETARY MOTION

MOST IMPORTANT MCQs ON KEPLER'S LAWS OF PLANETARY MOTION

Quiz

 

1. The orbits of planets around the sun are-
   1.   (a) circular
   2.   (b) parabolic
   3.   (c) elliptical
   4.   (d) straight
2. Which of the following statements are true?
   (i) the orbit of a planet is elliptical with the sun at one of its foci
   (ii) the line joining the planet and the sun sweeps equal areas in equal intervals of time
   (iii) the square of the mean distance of a planet from the sun is proportional to the cube of its orbital period
   1.   (a) only (i) and (ii)
   2.   (b) only (ii) and (iii)
   3.   (c) only (i) and (iii)
   4.   (d) all are correct
3. According to Kepler’s law the relationship between T (time period of revolution of a planet) and r (the semi-major axis of the ellipse) is-
   
   1.   (a) T2 ∝ r
   2.   (b) T2 ∝ r2
   3.   (c) T2 ∝ r-3
   4.   (d) T ∝ r3/2
4. Which of the following graphs represent the motion of a planet about the sun?
   
   1.   (a)
   2.   (b)
   3.   (c)
   4.   (d)
5. The time period of a satellite is 5 hours. If the separation between the earth and the satellite is increased to 4 times, what will be the new time period?
   1.   (a) 20 hours
   2.   (b) 10 hours
   3.   (c) 80 hours
   4.   (d) 40 hours
6. The time period of revolution of planet A around the sun is 8 times that of B. How many times the distance of A from the sun is greater than that of B from the sun?
   1.   (a) 2
   2.   (b) 3
   3.   (c) 4
   4.   (d) 5
7. A planet moving around sun sweeps out area A1 in two days, A2 in three days and A3 in six days. Then the relation between A1, A2, and A3 is-
   1.   (a) 3A1 = 2A2 = A3
   2.   (b) 2A1 = 3A2 = 6A3
   3.   (c) 3A1 = 2A2 = 6A3
   4.   (d) 6A1 = 3A2 = 2A3

STD-VI, STRUCTURE AND FUNCTION OF PLANTS & WORK AND ENERGY, Extra MCQs

 1.  Pick the odd one out-

(a) Sepals

(b) Stigma

(c) Ovary

(d) Style

 

ANS: Sepals

 

2.  The total number of whorls, in a flower, is/are-

(a) one

(b) two

(c) three

(d) four

 

ANS: four

 

3.  The sea creature that can produce significant amounts of electricity is the-

 

ANS: Electrical eel

 

4.  The _____ attaches a single flower to the inflorescence.

 

ANS: Pedicel

 

5.  The inside of electric bulb is filled with an _____ gas like argon or nitrogen.

 

ANS: inert

 

STD-VI, WORK AND ENERGY, EXERCISE QUESTION ANSWERS

 A.     FILL IN THE BLANKS.

1.      The work done depends upon the ____ applied and the _____ produced.

Ans: force, displacement

2.      _______ is the capacity to do work.

Ans: Energy

3.      _____ energy, stored in a battery, can be used to produce light in a torch.

Ans: chemical

4.      ______ is the main source of light energy.

Ans: Sun

5.      An electric bell produces sound from ______ energy.

Ans: electrical

B.      WRITE TRUE OR FALSE FOR THE FOLLOWING STATEMENTS.

 

1.      Work is done whenever a force is applied on a given object.                False

2.      A stationery ball does not possess kinetic energy.                                  True

3.      A ball raised to a height, is said to possess chemical energy.                False

4.      The motion, of the blades of a fan, is due to mechanical energy.         True

5.      Sound is a form of energy.                                                                        True

 

C.      TICK THE CORRECT OPTION.

 

1.      In which of the following situations, no ‘work’ is being done?

(a)   Shifting a box of biscuits from a lower shelf to a higher shelf in the kitchen

(b)   Throwing a ball

(c)    Pushing a baby stroller on a road

(d)   Just holding a book in your hand for two minutes

      Ans: just holding a book in your hand

STD-X, HUMAN EYE AND THE COLOURFUL WORLD- Scattering of Light, Most important MCQs

 

1.  The scattering of light by colloidal solution is called-

(a) Tyndall effect

(b) Raman effect

(c) Colloidal effect

(d) Refraction effect

 

ANS: Tyndall effect

 

2.  Which phenomenon is responsible for making the path of light visible?

(a) Tyndall effect

(b) Total internal refraction effect

(c) Colloidal effect

(d) Refraction effect

 

ANS: Tyndall effect

 

3.  Which of the following is not an example of Tyndall effect?

(a) When a fine beam of light enters a smoke filled dark room through a small hole

(b) Twinkling of stars

(c) When sunlight passes through a canopy of dense forest in misty conditions.

(d) Shinning a beam of flashlight into the glass of milk

 

ANS: Twinkling of stars

 

4.  The colour of the scattered light depends on ____ of the scattering particles.

(a) colour

(b) speed

(c) size

(d) number

 

ANS: size

 

5.  Fine particles mostly scatter ______.

(a) shorter wavelength such as blue

(b) longer wavelength such as blue

(c) shorter wavelength such as red

(d) longer wavelength such as red

 

ANS: shorter wavelength such as blue

 

6.  Large size particles mostly scatter-

(a) shorter wavelength such as blue

(b) longer wavelength such as blue

(c) shorter wavelength such as red

(d) longer wavelength such as red

 

ANS: longer wavelength such as red

 

7.  The main reason behind the phenomenon of scattering of light is,

(a) light has large wavelength value of the order of few metres

(b) light wave can travel through vacuum

(c) light waves are deflected by fine particles, molecules present in the air

(d) Sun light is composite light with blue as its major constituent

 

ANS: Light waves are deflected by fine particles, molecules present in the air

 

8.  If size of particles is comparable to wavelengths of incident light then,

(a) scattering does not take place

(b) all wavelengths will get scattered equally

(c) scattered light appears violet

(d) internal reflection takes place

 

ANS: all wavelengths will get scattered equally

 

STD-X, ATMOSPHERIC REFRACTION: Twinkling of Stars, Advanced Sunrise and Sunset, Most important MCQs

 1.  The air layer of atmosphere whose temperature is less then the hot layer behave as optically,

(a) denser medium
(b) rarer medium
(c) inactive medium
(d) either denser or rarer medium

 

ANS: denser medium

 

2.  Refraction of light by the earth’s atmosphere due to variation in air density is called
(a) atmospheric reflection
(b) atmospheric dispersion
(c) atmospheric scattering
(d) atmospheric refraction

ANS: atmospheric refraction

 

3. The word optical density of atmosphere refers to- 

(a) thickness of atmosphere

(b) brightness of atmosphere

(c) degree to which atmosphere reduces intensity of light passing through it

(d) degree to which atmosphere focuses light

 

ANS: degree to which atmosphere reduces intensity of light passing through it.

 

4.  Twinkling of stars is due to atmospheric

(a) dispersion of light by water droplets

(b) atmospheric refraction of light by different layers of varying refractive indices

(c) scattering of light by dust particles

(d) internal reflection of light by clouds.

 

ANS: atmospheric refraction of light by different layers of varying refractive indices

 

5.  As light from a far off star come down towards the earth

(a) it bends away from the normal

(b) it bends towards the normal

(c) it does not bend at all

(d) it reflects back

 

ANS: it bends towards the normal

 

6.  The stars appear shifted from their actual position due to the phenomenon of,

(a) diffraction of light

(b) scattering of light

(c) refraction of light

(d) internal reflection of light

 

ANS: refraction of light

 

7. The stars twinkle but the planets do not twinkle at night because-

(a) the stars are big but the planets are smaller

(b) the stars are very much nearer but planets are far off

(c) the stars are far off but planets are nearer to the earth

(d) planets produce light which is reflected by stars

 

ANS: the stars are far off but planets are nearer to the earth

 

8.  The planets do not twinkle because-

(a) atmospheric refraction does not take place

(b) planets are equivalent to a point source

(c) planets are equivalent to an extended source

(d) planets do not have atmosphere

 

ANS: planets are equivalent to an extended source

 

9. Advanced sunrise and delayed sunset are explained on the basis of 

(a) dispersion of light

(b) scattering of light

(c) Tyndall effect

(d) atmospheric refraction

 

ANS: atmospheric refraction

 

10. The Sun is visible before the sunrise and after the sunset because of the phenomenon of ______.  

(a) reflection

(b) refraction

(c) dispersion

(d) polarization

 

ANS: refraction