Question

Consider the figure given below

In the above figure, it is shown that three planes are intersecting at a point $O$, such that these three planes are mutually perpendicular to each other.
The distances measured from $XY$-plane upwards in the direction of $OZ$ are taken as ...A ... and those measured downwards in the direction of $O{Z}^{\prime }$ are taken as ...B.... Similarly, the distance measured to the right of $ZX$-plane along $OY$ are taken as ...C... to the left of $ZX$-plane and along $O{Y}^{\prime }$ as ...D..., in front of the $YZ$-plane along $OX$ as ...E... and to the back of it along $O{X}^{\prime }$ as ...F... . In the above passage, $A,B,C,D,E$ and $F$ refer to

• A. $A,B,C\to$ negative and $D,E,F\to$ positive
• B. A, B, C $\to$ positive and $D,E,F\to$ negative
• C. A, E, C $\to$ positive and $B,D,F\to$ negative
• D. $A,C,E\to$ negative and $B,D,F\to$ positive

Answer 1

Answer: (C)

These problems are based on coordinate axes and coordinate planes in three dimensional space.

The distances measured from $XY$-plane upwards in the direction of $OZ$ are taken as positive and those measured downwards in the direction of $O{Z}^{\prime }$ are taken as negative. Similarly, the distance measured to the right of ZX-plane and along OY are taken as positive, to the left of ZX-plane and along $O{Y}^{\prime }$ as negative, in front of the $YZ$-plane along $OX$ as positive and to the back of it along $O{X}^{\prime }$ as negative.