The Panasonic TX-40FS503B TV supports 4K UHD resolution (3840 x 2160 pixels), so it is compatible with the UHD output from Sky Q. When using Sky Q with your TV, you should be able to enjoy content in 4K resolution, provided that you have a Sky Q subscription that provides access to UHD content and the appropriate HDMI cables are used.
Make sure to check your TV settings to confirm that it is set to display the highest resolution available, and