At which temperature will water boil when the external pressure is 31 kpa

TO solve this problem, we simply have to find for the temperature of saturated water when the external pressure is 31 kPa. When the atmospheric pressure above a liquid equals its vapour pressure, then that liquid will boil. From the tables, the temperature at 31 kPa is about:

70 °C

adding a(n) to an electric circuit would increase the magnetic field around a wire;

b. solenoid

a solenoid is a type of electromagnet whose purpose is to generate a controlled magnetic field.

if the purpose of the solenoid is instead to impede changes in the electric current, a solenoid can be more specifically classified as an inductor rather than an electromagnet.