Final answer:
Raghav has to press down on the screwdriver's handle to pop up the lid of the jam can due to the principle of leverage in physics.
Step-by-step explanation:
In order to pop up the lid of a can of jam, Raghav has to press down on the screwdriver's handle. This is because of a principle in physics known as leverage. Leverage is the ability to exert pressure or force through the use of a lever, such as a screwdriver. When Raghav presses down on the handle of the screwdriver, the force is transmitted to the other end of the screwdriver, allowing him to pop up the lid of the jam can.
One way to understand this principle is by considering a see-saw or a teeter-totter. When someone sits on one end and presses down, it causes the other end to rise up. Similarly, when Raghav presses down on the screwdriver's handle, he is applying a force that is then translated to the other end of the screwdriver, which helps to pop up the lid of the can.