Physics Questions and Answers

The correct statement is:
The acceleration of P is equal to that of Q and both are in the same direction.
When ball P is released from the roof of the building, it falls freely under the influence of gravity. Similarly, when ball Q is thrown vertically upward, it initially moves upward but is also under the influence of gravity, which acts to slow it down and eventually makes it fall back down.
Both balls, P and Q, are subjected to the same acceleration due to gravity (assuming no other forces are acting on them), which is approximately 9.8 m/s² near the surface of the Earth, and this acceleration acts in the downward direction. Therefore, the acceleration of P is equal to the acceleration of Q, and both are in the same direction, which is downward.

The colors of the visible light spectrum with the shortest and longest wavelengths respectively are:

Violet and red.

Violet light has the shortest wavelength among visible colors, while red light has the longest wavelength. The visible light spectrum, in order of increasing wavelength, goes from violet to blue, green, yellow, orange, and finally red.

The property of a body that determines the direction of heat flow when the body is in contact with another body is the temperature.

Heat naturally flows from a body at a higher temperature to a body at a lower temperature. Temperature is a measure of the average kinetic energy of the particles in a substance. When two objects at different temperatures come into contact, heat energy tends to transfer from the warmer object to the cooler one until they reach thermal equilibrium (they are at the same temperature). This is known as the second law of thermodynamics, which describes the direction of heat flow.

The sagging of overhead electrical wires is caused by linear expansion.

Linear expansion is the tendency of materials to expand in length when they are heated. When overhead electrical wires are heated by the sun, they expand and sag.

A direct current (DC) cannot pass through a parallel plate capacitor because the dielectric between the plates is non-conducting.

In a parallel plate capacitor, two conductive plates are separated by a dielectric material (usually an insulator). When a voltage (potential difference) is applied across the plates, it creates an electric field between them, which stores electrical energy in the form of electric potential. The dielectric material between the plates is a non-conducting material, which means it does not allow the flow of electric current. Therefore, in a DC circuit, where current is the flow of charge over time, current cannot flow through the dielectric. Instead, the dielectric serves to store energy in the electric field between the plates without allowing the passage of charge.

Thermometer E would register the highest temperature since the hot metal is suspended from its side

E = 2V, r = 0.5Ω, I = 0.4A, P = ?

 E = I( R + r )

R = \(\frac{ E}{I} - r \)

R =  \(\frac{ 2}{0.4} - 0.5\)

R = 5 - 0.5 = 4.5Ω

When a lightweight body and a massive body are acted upon by the same force for the same time, the momenta of both bodies remain the same.

Given that the momenta of both the heavy and light bodies are the same, it follows that the light body possesses a higher velocity compared to the heavy body.

The specific latent heat of vaporization of lead is the amount of thermal energy required to change 1 kg of molten lead to vapor at constant temperature and pressure.

The statement that explains the observation is:

The most energetic molecules leave the surface and escape into the air.

This phenomenon is known as evaporation. In a liquid, molecules have varying energies, and the molecules with higher kinetic energies (the most energetic ones) are more likely to overcome the attractive forces within the liquid and transition into the gaseous phase. These molecules escape from the surface of the liquid into the air, gradually reducing the amount of liquid in the open dish. Evaporation is a process that occurs continuously as long as there is a liquid exposed to the air.