In which of the following processes, heat is neither absorbed nor released by a system?

In a double slit experiment, when light of wavelength 400 nm was used, the angular width of the first minima formed on a screen placed 1m away, was found to be 0.2^o. What will be the angular width of the first minima, ($$\mu $$_water = 4/3) if the entire experimental apparatus is immersed in water?

A cylinderical conductor of radius R is carrying a constant current. The plot of the magnitude of the magnetic field. B with the distane d from the centre of the conductor, is correctly represented by the figure :

In the circuits shown below, the readings of voltmeters and the ammeters will be :