In view of the position which arises from the aforesaid discussion it is really unnecessary for us to go into and decide the question whether, in cases where the arbitration clause contained in the underlying Commercial Contract is so widely worded as to include 505 within its scope the questions of its existence, validity or effect (scope), the decided cases have made a distinction between questions as to the existence or validity of the agreement on the one hand and its effect (scope) on the other and have held that in the case of the former those questions cannot be decided by the arbitrators, as by sheer logic the arbitration clause must fall along with the underlying Commercial Contract which is either non existent or illegal, while in the case of the latter it will ordinarily be for the arbitrators to decide the effect (scope) of the arbitration agreement as is contended for by Counsel for G.E.C., because both under the scheme of the Foreign Awards Act as well as under the general law of arbitration obtaining in England and in India, the decision of the arbitrator on the question of his own jurisdiction will have to be regarded as provisional or tentative, subject to final determination of that question by the Court.