Indian army has published the notification for SSC Tech 56 men and SSC Tech 27 women for the course commencing at OTA Chennai from April 2021
Which one of the following is the chemical formula of gypsum?
CaSO4.2H2O
Ca2SiO4
2CaSO4 .H2O
CaSO4
Which one of the following statements about the law of conservation of mass is correct?
A given compound always contains exactly same proportion of elements.
When gases combine in a reaction, they do so in a simple ratio by volume, provided all gases are at room temperature
Matter can neither be created nor destroyed
Equal volumes of all gases at same temperature and pressure contain equal number of molecules.
The wavelength of X-rays is of the order of
1 A
1 μm
1 mm
1 cm
If the focal length of a convex lens is 50 cm, which one of the following is its power?
+2 dioptre
+0.02 dioptre
-0.5 dioptre
+0.5 dioptre
The coefficient of areal expansion of a material is 1.6 × 10-5 K-1. which one of the following gives the value of coefficient of volume expansion of this material?
0.8 × 10-5 K-1
2.4 × 10-5 K-1
3.2 × 10-5 K-1
4.8 × 10-5 K-1
