1.a sphere cant roll on

a. smooth horizontal surface     b.smooth inclined surface

c. rough horizontal surface        d.rough inclined surface

(confused between a & b.shouldn't both be correct?)

 

2.angular velocity of engine of a scooter is propotonal to the petrol input per second.the scooter is moving on a frictionless road with uniform velocity.if petrol input is increased by 10%,the linear velocity of the scooter is increased by

a.80%   b.10%     c. 20%    d.0%