✓ 4 MARKS
Case Study
🔥 APPEARED IN 3 BOARD SETS
Electrical transmission wires which are laid down in winters are stretched tightly to accommodate expansion in summers.
Two such wires lie along the following lines :
$l_1 : \frac{x+1}{3} = \frac{y-3}{-2} = \frac{z+2}{-1}$
$l_2 : \frac{x}{-1} = \frac{y-7}{3} = \frac{z+7}{-2}$
Based on the given information, answer the following questions :
(i) Are the lines $l_1$ and $l_2$ coplanar ? Justify your answer.
(ii) Find the point of intersection of the lines $l_1$ and $l_2$.
01 // VERIFIED BOARD OCCURRENCES
| Year | Paper Code | Set | Position |
|---|---|---|---|
| CBSE 2022 | Series 65-1 | Set 1 | Question 14 |
| CBSE 2022 | Series 65-1 | Set 2 | Question 14 |
| CBSE 2022 | Series 65-1 | Set 3 | Question 14 |
02 // OFFICIAL CBSE MARKING SCHEME BREAKDOWN
- Step 1: Stating the fundamental formula / law statement (+1 Mark)
- Step 2: Intermediate mathematical substitution or proof steps (+1 Mark)
- Step 3: Correct final value or conclusion with mandatory SI units (+1 Mark)