Question

Assertion: A crowbar is used to lift heavy loads.
Reason: A simple machine can be made as a force multiplier.
$(A)$ Both assertion and reason are correct and the reason is the correct explanation of assertion.
$(B)$ Both assertion and reason are correct and the reason is not the correct explanation of assertion.
$(C)$ The assertion is correct and the reason is incorrect.
$(D)$ Both assertion and reason are incorrect.

Answer 1

The directions of the force are often changed by reversing the direction of the current. This causes the reverse on the force field through the wire. This reverses the force within the desired location. There are spreads of machines, magnets or motors which help to lift objects of small weight. There are few machines, motors or magnets which may also help to lift heavy loads.

Complete step-by-step solution:
There are many numbers of machines which help to lift heavy loads. To lift those heavy loads, machines need levers. Generally, machines that belong to second-class levers are accustomed to lifting heavy loads such as machines including the pulley, crane, crowbar, etc. These devices also change the direction of the force within the desired direction or also can also speed up the motion.
Magnets help to form a tight seal on the doors of refrigerators and freezers. Magnets are accustomed to transform mechanical energy into electric energy. Electromagnets are accustomed to lifting heavy loads. Changing the direction of the magnetic field can even change the direction of the force.
Motors are accustomed to transform electrical energy into mechanical energy. Motors may be used to lift an object of $100kg$. By inverting the polarity of applied voltage, the directions of motors are often turned in either direction. Hence, the force can actually be created within either direction using motors.
From the above discussion, option A is correct. Both assertion and reason are correct and the reason is the correct explanation of assertion.

Note: A gearbox may be a machine that is often used as a speed reducer whereas a lever is employed as a force increaser. Stepper motors may be accustomed to lift an object which weighs$100kg$. Typically, electromagnets are employed to lift electromagnets and not permanent magnets because it doesn’t lose its magnetic property. Magnets are fixed inside the machine which helps to lift heavy objects furthermore and speeds up the motion.