Physics

The two slits of young double slit experiment are separated by a distance of 0.03mm. An interference pattern on the screen is 1.5 m away. The fourth fringe is at distance of 1 m from the central maximum. Calculate wavelength of light used.

A steel and brass wire, each of length 50 cm and cross-sectional area 0.005 cm2 hang from ceiling and are 15 cm apart. Lower ends of the wires are attached to a light horizontal bar. A suitable downward load is applied to the bar so that each of the wire extends in length by 0.1 cm. At what distance from the steel wire the load must be applied?



1. a. 75 cm
2. b. 5 cm
3. c. 10 cm
4. d. 3 cm

The bob of a swinging second's pendulum (one whose time period is 2s) has a small speed v0 at its lowest point. Its height from this lowest point, 2.25s after passing through it is

1. a. v02/2g
2. b. v02/g
3. c. v02/4g
4. d. gv02/4g