A: Superconducting materials are not good conductors at room temperature asthe normal metals are at room temperature.
R: Superconductivity is observable only if the applied magnetic field is below the critical field.
(1) Both A and R are true, and R is the correct explanation of A.
(2) Both A and R are true, but R is NOT the correct explanation of A.
(3) A is true, but R is false.
(4) A is false but R is true.
