Central Board Of Secondary Education – ( CBSE )

Recommended Question & Answers for Class 12

1. Let S = {1, 2, 3} Determine whether the function f: S à S defined as below have inverse. f = {(1, 1), (2, 2), (3, 3)}

f is one – one and onto, so that f is invertible with inverse f-1 = {(1, 1) (2, 2) (3, 3)}

2. Refractive index of a solid is observed to have the same value along all directions. Comment on the nature of this solid. Would it show cleavage property?

As the solid has same value of refractive index along all directions, it is isotropic in nature and hence amorphous. Being amorphous solid, it will not show a clean cleavage and when cut, it will break into pieces with irregular surfaces.

3. Define the term electric dipole moment of a dipole. State its S.I. unit

τ = OE sin θ
If E = 1 unit, θ = 90°, then τ = P
Dipole moment may be defined as the torque acting on an electric dipole, placed perpendicular to a uniform electric dipole, placed perpendicular to a uniform electric field of unit strength.
or Strength of electric dipole is called dipole moment.
|P→|=q|2a|
∴ SI unit is Cm.