At any time when

1. the office of a Judge of a High Court is vacant; or
2. a Judge of a High Court is absent or is unable to perform the functions of his office due to any other cause; or
3. for any reason it is necessary to increase the number of Judges of a High Court,

the President may, in the manner provided in clause (1) of Article 193, appoint a person qualified for appointment as a Judge of the High Court to be Additional Judge of the Court for such period as the President may determine, being a period not exceeding such period, if any, as may be prescribed by law.