Explanation:

• A superconductor is a substance that conducts electricity without resistance when it becomes colder than a "critical temperature." At this temperature, electrons can move freely through the material.
• No heat, sound or any other form of energy would be released from the material when it has reached critical temperature (Tc), or the temperature at which the material becomes superconductive.
• The critical temperature for superconductors is the temperature at which the electrical resistivity of metal drops to zero.
• Prominent examples include aluminium, niobium, magnesium diboride, etc.
• A superconducting material kept in a magnetic field expels the magnetic flux out its body when cooled below the critical temperature and exhibits perfect diamagnetism.
• It is also called the Meissner effect which simply means that magnetic lines do not pass through superconductors in a magnetic field.

Hence only statement 1st is correct.