25. A and B are two square plates of same metal and same thickness but length of B is twice that of A. Ratio of resistances of A and B is ed (a) 4:1 (c) 1:1 (b) 1:4 (d) 1:2 0

A and B are two square matrices of same order. If AB =B^(-1), " then " A^(-1) =____.

A B C and B D E are two equilateral triangles such that D is the mid-point of B C . The ratio of the areas of the triangles A B C and B D E is 2:1 (b) 1:2 (c) 4:1 (d) 1:4

Two square metal plates A and B are of the same thickness and material. The side of B is twice that of A. These are connected as shown in series. If the resistances of A and B are denoted by R_(A) and R_(B) then (R_(A)//R_(B)) is :

If A and B are square matrices of the same order such that B=-A^(-1)BA, then (A+B)^(2)

Two square metal plates A and B are of same thickness and material. The side of B is twice that of A. These are connected in series, as shown in Fi. 4.3. Find the ratio R_(A)//R_(B) of the resistance of the two plates.

If the ratio of the areas of two square is 9:1, then the ratio of their perimeters is (a) 2:1 (b) 3:1 (c) 3:2 (d) 4:1

If the ratio of volumes of two spheres is 1:8, then the ratio of their surface area is 1:2 (b) 1:4 (c) 1:8 (d) 1:16

If the ratio of volumes of two spheres is 1:8, then the ratio of their surface area is 1:2 (b) 1:4 (c) 1:8 (d) 1:16