In respect of the difference of the gravitational force from electric and magnetic forces, statement (b) is true. Gravitational force is attractive only, whereas the electric and the magnetic forces are attractive as well as repulsive. For example, like electric charges repel and opposite charges attract each other. Similarly, like magnetic poles repel and opposite magnetic poles attract each other. It should be noted that: Gravitational Force –Weakest force but of infinite range. Weak Nuclear Force – Next weakest force but of short range. Electromagnetic Force – Stronger with infinite range. Strong Nuclear Force – Strongest but with short range.