The centre distance between the pulleys for an open belt drive is

Question

  If the angle of wrap on smaller pulley of diameter 250mm is 120⁰ and diameter of larger pulley is twice the diameter of smaller pulley, then the centre distance between the pulleys for an open belt drive is                         

         (a)1000 mm                   (b) 750mm

       (c) 500mm                        (d) 250mm