190. Assertion : Though the distances of stars from the earth vary, they are assumed to be studded to a celestial sphere. Reason : The linear size of the sphere is irrelevant as all the six elements of the astronomical triangle are only considered, and not the distances of terrestrial triangle.

191. Assertion : The observation of stars at elongation is found inconvenient in high latitudes. Reason : The star at elongation is always at an altitude greater than the observer's latitude,

192. Consider the following statements regarding spherical trigonometry 1. A section of a sphere is called a great circle if the cutting plane passes through the centre of the sphere. 2. A section of a sphere is called a small circle if the plane cutting the surface does not pass through the centre of the sphere. 3. The shortest distance between any two points on the surface of a sphere is the straight line joining them. 4. A sphere is a solid formed by the revolution of a circle about the diameter. Of these statements :

193. Consider the following properties of a spherical triangle 1. The sum of three angles is less than 37t and greater than 7t 2. The sum of any two angles is smaller than the third 3. The smaller angle is opposite the smaller side and vice-versa. 4. Any angle is less than two right angles or n. Of these statements

194. Consider the following statements from the following : 1. The imaginary sphere of infinite radius, the centre of which is the earth is called celestial sphere. 2. The stars continually change their positions 3. In practical astronomy, we are only concerned with the distances of the celestial bodies from the earth 4. All celestial bodies appear to revolve from east to west round the celestial pole Of these statements:

195. Assertion A: The altitude and azimuth system of coordinates of heavenly-bodies is not suitable Reason R Due to the diurnal motion of the stars, the coordinates go on changing Of these statements:

196. Consider the following statements :Assertion A: The right ascension and declination system of coordinates is most convenient for specifying the position of heavenly bodies Reason R: Both right ascension and declination are constant Of these statements:

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