Explanation

In a closed organ pipe, the fundamental frequency is f = v / 4L.  

If both ends are opened, it behaves like an open pipe, and the fundamental frequency becomes f' = v / 2L.

So, f' = 2f.

Explanation

The reverse process of X-ray production is related to the "photoelectric effect". 

Photoelectric effect: In this process, a high-energy photon interacts with an atom, transferring all its energy to an electron and ejecting it from the atom.

This is the reverse of X-ray production, where electrons are accelerated to high speeds and generate X-rays when they collide with a target atom. 

Explanation

Atto (a) = 10⁻¹⁸

Femto (f) = 10⁻¹⁵

Nano (n) = 10⁻⁹

Peta (P) = 10¹⁵

So, Atto has the smallest (lowest) value.

Explanation

Explanation

Explanation

Explanation

• A magnifying glass, also known as a convex lens.
• It forms an enlarged virtual image that is upright.

The image formed by a magnifying glass:

• Image type: Virtual
• Orientation: Upright
• Size: Enlarged

Explanation

Latent heat of fusion is the energy required to change a solid into a liquid (or vice versa) without changing its temperature. 

Latent heat of vaporization is the energy required to change a liquid into a gas (or vice versa) without changing its temperature.

Explanation

The spring constant (k) represents the force required to stretch or compress a spring by a certain distance.

The unit of spring constant is Newton per meter (N/m) or Newton per meter^-1 (Nm^-1).

Explanation

• ISA (Iranian Space Agency) was established in 2004.
• The Iranian Space Agency is responsible for the national space program of Iran.