GEOLOGY

Detailed explanation-1: -The orthorhombic crystal has axial units in the ratio of 0.424 : 1: 0.367. The miller indices of a crystal face whose intercepts are in the ratio 0.212 :1 :0.183 will be :-a)2 : 1 : 2b)1 : 2 : 1c)4 : 1 : 4d)2 : 1 : 1Correct answer is option ‘A’.

Detailed explanation-2: -By calculation, the miller indices of 2a, 3b, 4c is 6, 4, 3. Hence option 1 is correct.

Detailed explanation-3: -If a plane is parallel to an axis, its intercept is at infinity and its Miller index is zero. A generic Miller index is denoted by (hkl). If a plane has negative intercept, the negative number is denoted by a bar above the number. Never alter negative numbers.

Detailed explanation-4: -We know that Miller indices of a plane are the reciprocals of the intercepts of that corresponding to unit length. Thus, intercepts are a:b:c=1:2:3. (or) We can take L.C.M and by taking L.C.M, we get the value of miller indices as 6, 3, 2.

Detailed explanation-5: -Step 1: Identify the intercepts on the x-, y-and z-axes. Step 2: Specify the intercepts in fractional co-ordinates. Step 3: Take the reciprocals of the fractional intercepts. Other Examples. 21-Feb-2022