Adouble-slit diffraction pattern is formed on a distant screen. if the separation between the slits decreases, what happens to the distance between interference fringes? assume the angles involved remain small.

the effect cannot be determined unless the distance between the sits and the screen is known.
the distance between interference fringes increases.
the distance between interference fringes remains the same.
the distance between interference fringes also decreases.

Which material produces static charge when rubbed?

Steam is generated in a boiler of a cogeneration plant at 10 mpa and 450°c at a steady rate of 5 kg/s. in normal operation, steam expands in a turbine to a pressure of 0.5 mpa and is then routed to the process heater, where it supplies the process heat. steam leaves the process heater as a saturated liquid and is pumped to the boiler pressure. in this mode, no steam passes through a condenser, which operates at 20 kpa. (a) determine the power produced in the turbine and the rate at which process heat is supplied in this mode. (b) determine the power produced in the turbine and the rate of process heat supplied if only 60 percent of the steam is routed to the process heater and the remainder is expanded to the condenser pressure. (3.32 mw; 9.69 mw; 4.25 mw; 5.82 mw)

What is friction? how does it affect the motion of an object?