Jee Main 2024 27 01 2024 Shift 1 - Question16
Question 16
The shortest distance between the line $\frac{x-1}{2}=\frac{y+1}{4}=\frac{z-1}{3}$ and $\frac{2 x-1}{5}=\frac{y-2}{3}=\frac{z}{6}$ is equal to
(1) 10 unit
(2) $\frac{7}{10}$ unit
(3) 0 unit
(4) $\frac{34}{\sqrt{1045}}$ unit
Show Answer
Answer: (4)
Solution:
$\frac{x-1}{2}=\frac{y+1}{4}=\frac{z-1}{3}$ and
$\frac{x-\frac{1}{2}}{\left(\frac{5}{2}\right)}=\frac{y-2}{3}=\frac{z}{6}$,
$\overrightarrow{a _1}-\overrightarrow{a _2}=\frac{1}{2} \hat{i}-3 \hat{j}+\hat{k}$
$\overrightarrow{n _1} \times \overrightarrow{n _2}=\left|\begin{array}{lll}\hat{i} & \hat{j} & \hat{k} \\ 2 & 4 & 3 \\ \frac{5}{2} & 3 & 6\end{array}\right|$
$=15 \hat{i}-\frac{9}{2} \hat{j}+(-4 k)$
$\vec{d}=\left|\frac{\left(\overrightarrow{a _1}-\overrightarrow{a _2}\right),\left(\overrightarrow{n _1} \times \overrightarrow{n _2}\right)}{\left|\overrightarrow{n _1} \times \overrightarrow{n _2}\right|}\right|$
$=\left|\frac{\frac{15}{2}+\frac{27}{2}-4}{\sqrt{225+\frac{81}{4}+16}}\right|$
$=\frac{\frac{34}{2}}{\sqrt{\frac{1045}{4}}}=\frac{34}{\sqrt{1045}}$ unit





