In Fig.56, give reasons why `l_1|(|l_2dotI s\ m_1\ |\ )|m_2?`

Explain , giving reason , which of the following sets of quantum number are not possible {:(a,n= 0 ,l = 0, m_(1) = 0, m_(s) = +1//2),(b,n= 1 ,l = 0, m_(1) = 0, m_(s) = -1//2),(c,n= 1 ,l = 0, m_(1) = 0, m_(s) = +1//2),(d,n= 2 ,l = 1, m_(1) = 0, m_(s) = -1//2),(e,n= 3 ,l = 3, m_(1) = -3, m_(s) = +1//2),(f,n= 3 ,l = 1, m_(1) = 0, m_(s) = +1//2):}

Explain given reasons, which of the following sets of quantum numbers are not possible. {:((a) n = 0 ",", l = 0",", m_l=0",", m_s = + 1//2),((b) n = 1 ",", l = 0",", m_l=0",", m_s = - 1//2),((c) n = 1 ",", l = 1",", m_l=-0",", m_s = + 1//2),((d) n = 2 ",", l = 1",", m_l=0",", m_s = - 1//2),((e) n = 3 ",", l = 3",", m_l=-3",", m_s = + 1//2),((f) n = 3 ",", l = 2",", m_l=0",", m_s = + 1//2):}

Two lines with direction cosines l_1,m_1,n_1 and l_2,m_2,n_2 are at righat angles iff (A) l_1l_2+m_1m_2+n_1n_2=0 (B) l_1=l_2,m_1=m_2,n_1=n_2 (C) l_1/l_2=m_1/m_2=n_1/n_2 (D) l_1l_2=m_1m_2=n_1n_2

Statement I . The combined equation of l_1,l_2 is 3x^2+6xy+2y^2=0 and that of m_1,m_2 is 5x^2+18xy+2y^2=0 . If angle between l_1,m_2 is theta , then angle between l_2,m_1 is theta . Statement II . If the pairs of lines l_1l_2=0,m_1 m_2=0 are equally inclinded that angle between l_1 and m_2 = angle between l_2 and m_1 .

Statement 1: The direction cosines of one of the angular bisectors of two intersecting line having direction cosines as l_1,m_1, n_1a n dl_2, m_2, n_2 are proportional to l_1+l_2,m_1+m_2, n_1+n_2dot Statement 2: The angle between the two intersection lines having direction cosines as l_1,m_1, n_1a n dl_2, m_2, n_2 is given by costheta=l_1l_2+m_1m_2+n_1n_2dot

If three mutually perpendicular lines have direction cosines (l_(1),m_(1),n_(1)),(l_(2),m_(2),n_(2)) and (L_(3),m_(3),n_(3)) then the line having direction cosines l_(1)+l_(2)+l_(3),m_(1)+m_(2)+m_(3), and n_(1)+n_(2)+n_(3) ,make an angle of

(l_(1),m_(1),n_(1)),(l_(2),m_(2),n_(2)),(l_(3),m_(3),n_(3)) are the direction cosines of three mutually perpendicular lines. If the line, whose direction ratios are l_(1)+l_(2)+l_(3),m_(1)+m_(2)+m_(3),n_(1)+n_(2)+n_(3) , makes angle theta with any of these three lines, then cos theta is equal to

Let (l_1,m_1,n_1) and (l_2,m_2,n_2) be d.c's of two lines.Then the lines are parallel if l_1/l_2=m_1/m_2=n_1/n_2 (Prove It)

If (l_(1), m_(1), n_(1)) , (l_(2), m_(2), n_(2)) are D.C's of two lines, then (l_(1)m_(2)-l_(2)m_(1))^2+(m_(1)n_(2)-n_(1)m_(2))^2+(n_(1)l_(2)-n_(2)l_(1))^2+(l_(1)l_(2)+m_(1)m_(2)+n_(1)n_(2))^2=