Most Repeated MDCAT Physics: Work, Power & Energy MCQs

Explanation

The correct answer is Volt. A volt measures the electrical potential difference and is defined as the work done per unit charge, expressed as 1V = 1J/1C. This means that one volt is equivalent to one joule of work done per one coulomb of charge. The other options are incorrect because:Hertz measures frequency, not related to work or charge.Watt measures power, defined as work per unit time, not charge.Joule is a unit of energy or work, not per unit charge.Half-life is a concept related to radioactive decay, not applicable to work or charge.

Explanation

Since K.E is inversely propotional to the mass the ratio of the masses will be inverted and would become 1:4.

Explanation

The correct answer is I, II, and III. Each scenario demonstrates kinetic energy due to the motion of the objects involved:Option I: The moving ball possesses kinetic energy, which can break a window upon collision.Option II: The hammer's motion imparts kinetic energy, allowing it to drive a nail.Option III: The stone, while initially moving upward, possesses kinetic energy. Even though this energy is converted to potential energy at the peak of its trajectory, the initial and final stages involve kinetic energy.Therefore, all options are correct as they all represent instances of kinetic energy due to motion.

Explanation

Since both bodies move under gravitational acceleration, that is the same throughout the movement and same for both bodies, therefore, option A is correct.

Explanation

Work done in a closed path is zero, since complete circle is a closed path, therefore, correct option is B i.e., zero.

Explanation

1 kilowatt (kW) is equal to 1000 watts (W).1 watt (W) is equal to 1 joule per second (J/s).1 hour is equal to 3600 seconds.1 kWh = 1000 W * 3600 s = 3,600,000 J = 3.

Explanation

A conservative field is a type of vector field in physics where the work done by a force in moving an object from one point to another is independent of the path taken. In other words, it depends only on the initial and final positions of the object. A. Gravitational field is conservative because the work done in moving an object from one position to another depends only on the initial and final positions, not the path taken. B. Electric field is conservative for the same reason as the gravitational field. The work done by an electric field in moving a charged particle depends only on the initial and final positions. C. Magnetic field is not a conservative field.

Explanation

When the body moves against the force of friction on a horizontal plane, the work done by the body is negative. This is because the force of friction acts in the opposite direction of the body's motion. When work is negative, it means that energy is being transferred from the body to the surroundings. In this case, the energy is being dissipated as heat due to the friction.