
10. When giving presentations, many people use a laser pointer to direct the attention of the...
When giving presentations, many people use a laser pointer to direct the attention of the audience to information on a screen. If a 2.8-mW (time-averaged power) pointer creates a spot on the screen that has a 3.2 mm radius, what is the radiation pressure on a screen that reflects all of the light? i. 1.86 x 10-9 Pa ii. 5.83 x 10-9 Pa iii. 5.80 x 10-7 Pa iv. 1.75 Pa When giving presentations, many people use a laser pointer...
A laser pointer of power P = 3.0 mW creates a spot on a screen that is 2.0 mm in diameter. Determine the maximum Electric and Magnetic fields incident on the screen. 1 dU P A dt A 1=c<u>=copic Emax = cBmax
A rectangular coil of wire N = 20 loops with sides a = 0.30m and b = 0.70m is positioned perpendicular to a uniform 0.55T magnetic field as shown below. It is quickly pulled from the field at constant speed perpendicular to B to a region where B drops abruptly to zero, At t=0, the middle of the coil in at the edge of the field. The total resistance of the loop in R = 46 ohms. It takes 0.0125...
A 3 mW red ( = 670 nm) laser pointer produces a 2 mm diameter spot on a screen. a) If we place a f = 1cm lens before the screen, and the radius of curvature of the wavefront reaching the lens is 2 m, find the waist of the focused light. b) The intensity of the light at the center of the beam is given by Imax= 2P/πw2(in W/m2). Calculate the maximum intensity at the focal point. c) If...