Concave lenses always produce virtual images when the object is placed within the focal length.

Magnetic field lines always form closed loops, indicating that magnetic field lines do not start or end but continue indefinitely.

Polarized light vibrates in a single plane, unlike unpolarized light which vibrates in multiple planes.

Power can be negative when work is done against the direction of motion, such as in friction. Therefore, the correct statement is that power can be negative.

The RMS speed is always greater than the average speed for a distribution of speeds in a gas.

Solids have a definite shape and volume due to the closely packed arrangement of their particles.

Sound waves are longitudinal waves, meaning the particle displacement is parallel to the direction of wave propagation.

Surface tension generally decreases with an increase in temperature due to increased molecular motion.

In the Bohr model, energy levels are quantized, meaning electrons can only exist in specific energy states.

In the Bohr model, only certain orbits (or energy levels) are allowed for electrons, which correspond to specific energy states.

The law of conservation of energy states that energy can neither be created nor destroyed, but can be transformed from one form to another.

Momentum is conserved in all types of collisions, provided no external forces act on the system.

The Heisenberg Uncertainty Principle states that there is a limit to the precision with which certain pairs of physical properties, such as position and momentum, can be known simultaneously.

The law of conservation of energy states that energy can be transformed from one form to another, but cannot be created or destroyed.

The photoelectric effect shows that only light above a certain frequency can cause the emission of electrons, regardless of intensity.

The uncertainty principle states that position and momentum cannot be known simultaneously with arbitrary precision in quantum mechanics.

Torque depends on the angle of application, as it is calculated using τ = F × d × sin(θ).

Total internal reflection requires that the light travels from a denser medium to a rarer medium, making the second statement true.

Viscosity is a scalar quantity that measures a fluid's resistance to flow.

X-rays are a form of electromagnetic radiation, similar to visible light but with much higher energy and shorter wavelength.

The first law states that energy is conserved, and heat cannot spontaneously flow from cold to hot without work being done.

A diverging lens causes parallel rays to diverge, making it impossible to focus light to a point.

In a perfectly inelastic collision, momentum is conserved, but kinetic energy is not.

A Wheatstone bridge can be used to measure both AC and DC resistances.

An ideal gas is defined as a gas that has no intermolecular forces and follows the ideal gas law under all conditions.

Electric field lines point from positive to negative charges and never cross each other.

Entropy is a measure of disorder, and it is constant in reversible processes, making both statements a and c true.

No work is done when moving a charge along an equipotential surface because the potential is constant.

Geostationary satellites have a period equal to the Earth's rotation period and remain in the same position relative to the Earth.

Gravitational field lines point towards the mass creating the field.