Answer:
A.B = -38
Explanation:
A = 2i + 9j and B = -i - 4j.
So, A.B = (2i + 9j).(-i - 4j)
= 2i.(-i) + 2i.(-4j) + 9j.(-i) + 9j.(-4j)
= -2i.i - 8i.j - 9j.i - 36j.j
since i.i = 1, j.j = 1, i.j = 0 and j.i = 0, we have
A.B = -2(1) - 8(0) - 9(0) - 36(1)
A.B = -2 - 0 - 0 - 36
A.B = -38
Answer:
material work function is 0.956 eV
Explanation:
given data
red wavelength 651 nm
green wavelength 521 nm
photo electrons = 1.50 × maximum kinetic energy
to find out
material work function
solution
we know by Einstein photo electric equation that is
for red light
h ( c / λr ) = Ф + kinetic energy
for green light
h ( c / λg ) = Ф + 1.50 × kinetic energy
now from both equation put kinetic energy from red to green
h ( c / λg ) = Ф + 1.50 × (h ( c / λr ) - Ф)
Ф =( hc / 0.50) × ( 1.50/ λr - 1/ λg)
put all value
Ф =( 6.63 ×
(3 ×
) / 0.50) × ( 1.50/ λr - 1/ λg)
Ф =( 6.63 × (3 × ) / 0.50 ) × ( 1.50/ 651×
- 1/ 521 ×)
Ф = 1.5305 ×
J × ( 1ev / 1.6 × J )
Ф = 0.956 eV
material work function is 0.956 eV
Answer:
electrons will migrate untill there is uniform distribution of charge .
and sphere became uniformly charged
Explanation:
as conducting sphere is charged positively it is given . the left side of sphere is charged positively . there is negative charge on the left side that will be attracted by positive charge of right side .
therefore electrons from left side will start migrate towards right side due to attraction of positive charge of right side .
therefore electron will start migrate uniformly .
electrons will migrate untill there is uniform distribution of charge .
and sphere became uniformly charged
Kinetic Energy:
Kinetic Energy is the energy of motion.
Mass:
Mass is the number of particles that a substance has
I think the correct graph would be
the THIRD GRAPH
6. D
7. D
8. B
let me know if you need clarification
