Answers for Practice test

 

Key Sheet

I

1)80 cal /gm 

2)A1

 3) Total internal reflection

4) n2/v - n1/ u = n2-n1/R 

5) A 

6) C 

7) S= Q/ m^t

8) 2.42

9) CaSO4 1/2 H2O 

10) Copper 

11) Bi focal length lens 

12) The Zeeman effect is the effect of splitting of a spectral line into several components in the presence of a static magnetic field.

III 

21. Laws of refraction state that:

The incident ray refracted ray, and the normal to the interface of two media at the point of incidence all lie on the same plane.

The ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant. This is also known as Snell's law of refraction.

22. a B        b C      c D.      d A 

23. n= c/v.   n= 300000/124000.    n= 2.42

24. 1) What is thermal equilibrium?

       2) When will say that they are in thermal equilibrium?

25) Methyl orange indicator is used in the strong acid weak base titration. The colour change of methyl orange depends upon the pH of the solution. In acidic medium means pH below 3.0 it shows red colour.

26) AS WE KNOW THAT, COPPER IS A GOOD CONDUCTOR OF HEAT. IN COOKING UTENSILS SUCH METALS ARE USED WHO ARE GOOD CONDUCTORS OF HEAT, SO THAT, THE FOOD GETS COOKED FAST AND WITHIN SHORT TIME. AS COPPER IS A GOOD CONDUCTOR, IT IS USED AT THE BASE OF COOKING UTENSILS.

27) H2SO4& HNO3 

28) According to Fermat's principle that light selects the shortest path to travel.

1. This is the reason for the propagation of light in straight lines.2. We use this principle, when we draw ray diagrams to find the image of an object formed by mirrors to illustrate the laws of reflection, refraction etc.