Science
- Give scientific reasons. a. When an object falls freely to the ground, its acceleration is uniform. When an object falls freely to the ground, it is under the effect of a constant force known as force of gravity. No other forces act on it.... 1
- Complete the sentences and explain them. Laws of motion a. The minimum distance between the start and finish points of the motion of an object is called the displacement of the object. => The shor... 1
- Complete the following table. u (m/s) a (m/s2) t (sec) v = u + at (m/s) 2 u (m/s) a (m/s²) t (sec) v = u + at (m/s) 2 4 3 14 10 5 2 20 u (m/s) a (m/s²) t (sec) s=ut + 1/2at² (m) 5 12 3 69 7 8 4 92 u (m/s) a (m/s²)... 1
- Clarify the differences Uniform and non-uniform motion. Uniform motion Non-uniform motion When an object covers equal distance in equal time interval, it is said to be in uniform motion. When an o... 1
- Clarify the differences Distance and displacement Distance Displacement It is defined as the length of the actual path travelled by an object in motion. It is defined as the shortest distanc... 1
- Match the first column with appropriate entries in the second and third columns and remake the table. S.no Column 1 Column 2 Column 3 1 Negative acceleration the velocity of object decreases A vehicle moving with the velocity of 10 m/s, stops... 1
- Why can an X-ray telescope not be based on the earth? X-rays are emitted from distant heavenly bodies. The rays coming towards the earth will be absorbed by the earth’s atmosphere and will go un... 1
- Why are optical telescopes located in uninhabited places on mountains? Optical telescopes situated on the surface of Earth, does not produce images of good quality of the following reasons: Intensity of light ra... 1
- Explain the construction of a radio telescope. These telescopes are used to see radio waves coming from space. It has one or more dishes of parabolic shape. The rays coming from the dista... 1
- Explain the construction of Galileo’s telescope. The Galileo’s telescope is made up of two or more convex lenses. The lens facing the object is called the objective lens which is made as la... 1
- Study the figure and answer the following questions What type of telescope is shown in the figure? a. Newtonian telescope is shown in the given figure. b. c. Both plane and spherical mirror is used in this telescope. The spherical mirror i... 1
- Which type of telescopes can be made using a concave mirror, convex mirror, plane mirror and a lens? Reflecting types of telescopes can be made using a concave mirror, convex mirror, plane mirror and a lens. Reflecting type of telescopes is... 1
- What are the difficulties in using ground based optical telescopes? How are they overcome? The difficulties faced in using ground based telescopes due to which it does not make good quality observations are: Intensity of light rays... 1
- Column ‘A’ Column ‘B’ (1) X-rays (a) GMRT (2) Optical telescope (b) ISRO (3) Indian radio telescope (c) Hubble ‘A’ Groups ‘B’ Groups (i) X-rays (d) Chandra (ii) Optical telescope (c) Hubble telescope (iii) Indian radio (a) GMRT (iv) Launching artifici... 1
- Fill in the blanks with the proper words. a. The wavelength of visible light is between a. The wavelength of visible light is between 400 nm and 800 nm. b. GMRT is used for radio waves. c. A certain X-ray telescope is named afte... 1