1) If the line r=(ˆi−2ˆj+3ˆk)+λ(2ˆi+ˆj+2ˆk) is parallel to the plane r.(3ˆi−2ˆj+mˆk)=10 , then the value of m is A) -2 B) 3 C) 2 D) -3 Answer: Option AExplanation:Given line, r=(ˆi−2ˆj+3ˆk)+λ(2ˆi+ˆj+2ˆk) is parallel to the plane r.(3ˆi−2ˆj+mˆk)=0 we know that, if line r= a+λ.b is parallel to plane r.n=d then , b.n=0 ∴ (2ˆi+ˆj+2ˆk).(3ˆi−2ˆj+mˆk)=0 6-2+2m=0 m=-2