Defence GK Questions 2026

Lysosomes are small membrane-bound sacs full of hydrolytic enzymes that digest worn-out parts and foreign material inside the cell. Lysosomes are formed from the Golgi apparatus and were discovered by Christian de Duve.

The resistance of a conductor depends on its material and shape, not on how much current flows through it. For a cylindrical conductor, R = ρL/A, where ρ is the resistivity of the material, L the length and A the area of cross-section.

Oxygen makes up about 21 per cent of dry air by volume, second only to nitrogen. Dry air near the ground is about 78 per cent nitrogen, 21 per cent oxygen and 0.93 per cent argon, which is the third most abundant gas.

DTTI is an India–US forum launched in 2012 to deepen defence trade and to develop and produce defence technology together.

The enzyme breaks the β-lactam ring that gives penicillin its power. Penicillin was discovered by Alexander Fleming in 1928 from the mould Penicillium notatum.

In an insulator the electrons are tightly bound to their atoms, so there are almost no free electrons to carry a current.

Zinc gives up electrons more readily than iron, so it corrodes first and keeps the iron safe. Coating iron or steel with a thin layer of zinc is called galvanisation.

An ECG records the electrical signals that make the heart muscle contract with each beat. Each heartbeat starts at the sino-atrial (SA) node, the natural pacemaker in the right atrium.

An echo is sound that bounces back from a hard surface such as a wall, cliff or hill and reaches our ears again.

Both stress and pressure are force per unit area, so both are measured in newton per square metre, or pascal (Pa).

A step-up transformer raises an alternating voltage, using more turns in its secondary coil than in its primary. A transformer works on electromagnetic induction and only with alternating current.

She won Miss Universe in 1994, becoming the first Indian to do so, but she never held the Miss World title.

For an object between F and P, the image forms behind the mirror, not at infinity. When an object is placed between the pole and the principal focus of a concave mirror, the reflected rays spread out and never meet in front of the mirror.

It comes from the rise and fall of sea tides, a renewable source that is not among the traditional fuels.

Heat makes the copper wire expand a little, and a longer pendulum swings a little more slowly. The time period of a simple pendulum is T = 2π√(L/g), so it grows with the square root of the length.

This is the law of conservation of energy: energy only changes from one form to another. In any isolated system the total energy stays the same.

Veer Baal Diwas is observed on 26 December to honour the martyrdom of the two youngest sons of Guru Gobind Singh.

This reverses the truth: a voltmeter has a very high resistance and an ammeter a very low one. An ammeter measures the current flowing through a circuit, so it is placed in series and the whole current passes through it.

As Ambassador of India to Italy she went aboard INS Trishul at Civitavecchia and met the ship's company, and she attended the cultural event hosted on the deck along with Vice Admiral Aurelio De Carolis, Fleet Commander and CINCNAV of the Italian Navy.

The frigate's crew went aboard this Italian aircraft carrier while both ships were at Civitavecchia, and the visit gave officers and sailors of the two navies a chance to compare professional practice and exchange experience at sea.