RRB JE GK Questions 2026

This is the complement law for addition, which corresponds to the OR operation. Whatever value A takes, one of A and its complement must be 1, and an OR gate gives 1 whenever any input is 1, so the expression is 1 in both cases.

Each input can take one of two values, so for three inputs the number of distinct combinations is two multiplied by itself three times, that is two raised to the power three, which is eight.

It is the only gate that takes a single input, and it simply reverses the logic level it receives, giving 1 for an input of 0 and 0 for an input of 1; because the output is the inverse or complement of the input, the circuit is called an inverter.

Adding two single bits gives a sum that is 1 when exactly one of the bits is 1 and 0 when both are 0 or both are 1, which is precisely the XOR rule; so in a half adder the sum line comes from an XOR gate.

The system was a work of pure mathematics for decades until Claude Shannon showed that it described electrical switching circuits exactly, which opened the way to digital computing.

In Boolean algebra a literal is any single appearance of a variable in an expression, whether it appears plain or with a bar over it.

An exclusive OR gate is a difference detector: it gives 1 for the combinations 0 and 1 or 1 and 0, and gives 0 when the inputs agree.

De Morgan's second theorem states that NOT of A AND B equals NOT A OR NOT B. The working rule is to break the bar and change the sign, so a dot under a complement becomes a plus once the complement is distributed over the variables.

Each of these gates alone is enough to build every other gate and so every logic circuit: a NAND with its two inputs tied together acts as a NOT, two NANDs in sequence give an AND, and a suitable arrangement of three gives an OR, and the same can be…

Read the table row by row. The output is 0 only when both inputs are 0, and it is 1 in the other three rows, including the row where both inputs are 1.

Curium is a radioactive man-made element with the symbol Cm and atomic number 96.

A catalytic poison is a substance that lowers or destroys the activity of a catalyst, usually because it sticks firmly to the active surface and leaves no room for the reactants.

Chemical equilibrium is a dynamic state: both reactions go on, but at the same speed, so no net change is seen.

The correct answer is Vedic Kavach, the post-quantum cryptography platform built by BISAG-N. The keys produced by the quantum link were integrated with it, and test messages were then encrypted and decrypted from end to end.

Both numbers describe the quality of the link: the key rate is how fast fresh secret material can be produced for encryption, and the error rate measures how often a photon is read wrongly, which in quantum key distribution also signals whether anyone has interfered with the channel.

QNu Labs supplied the hardware QKD device Armos, BISAG-N contributed the post-quantum cryptography platform Vedic Kavach along with one end of the link, and IIT Gandhinagar hosted the other end and provided the field setting.

That is the span over which the country's first free-space Quantum Key Distribution link was established, between the BISAG-N campus and IIT Gandhinagar, in a field trial run on the night of 27 and 28 September.

Earthquake waves fall into body waves, which travel through the interior of the Earth, and surface waves, which move along the surface, and the surface waves are called L waves, or long waves.

Charles’s law says that at constant pressure the volume of a fixed mass of gas is directly proportional to its absolute temperature, so V by T stays constant.

Coulomb’s law gives the force between two point charges at rest. It states that the force is directly proportional to the product of the two charges and inversely proportional to the square of the distance between them, and acts along the line joining them.