Question

A green laser operating at 532 nm shines light onto two-closely spaced slits. An interference pattern is created on a distant screen. If the fifth dark fringe appears on the screen at an angle of 0.12 degrees with respect to the center line, what is the slit separation distance? 1.85 mm 1.10 mm 5.55 mm 11.1 mm 4.62 mm Question 5 5 pts A charged particle traveling at a given speed enters a uniform magnetic field. The velocity vector of the particle is perpendicular to the magnetic field. Which of the following particle properties will change while in the magnetic field? Its speed. Its velocity Its kinetic energy All of the above (A, B, and C). None of the above (not A, B, or C).

Answer 1

1) Given:

The wavelength of light =

X= 532nm

The fifth dark fringe is obtained at an angle of 0.12 degrees with respect to the central line.

let the separation of the slits be d.

The path difference for the formation of nth dark fringe is

(2η – 1) Δε Ε 2

The relation between the angular distance of the fringe, wavelength and slits separation is

-----(i)

sind р

Therefore, using the equation (i):

sin0.12° (2n-1) 2 d (2n - 1) 2d

→ d = (2n-1) 2 sin 0.12

d= (2 * 5 – 1) * 532 * 10- 2 sin 0.12 = 0.00114m = 1.14mm 1.1mm

Therefore, the correct option is the 2nd option.[answer]

5) The magnetic force on a moving charged particle is given by

F =qū x B

The force vector is perpendicular to both the velocity vector and the magnetic field vector.

As the force vector is perpendicular to the velocity vector, the force can only change the direction of velocity, it cannot change the magnitude of velocity.

Therefore, the speed of the particle and kinetic energy of the particle remains constant, but velocity changes.

therefore, correct option is 2nd option.[answer]