The emission spectrum of hydrogen is a line spectrum, consisting of discrete lines corresponding to specific wavelengths of light emitted by electrons transitioning between energy levels.

An ideal fluid is defined as being incompressible and non-viscous, meaning it has no internal friction.

Viscosity is the measure of a fluid's resistance to flow. Higher viscosity means the fluid flows less easily.

Boyle's Law states that the pressure of a gas is inversely proportional to its volume at constant temperature.

A Light Emitting Diode (LED) is based on the principle of a p-n junction, emitting light when current flows through it.

All of the above devices operate on the principle of electromagnetic induction.

An electric motor uses electromagnetic induction to convert electrical energy into mechanical energy.

An electric motor operates based on the magnetic effects of current, converting electrical energy into mechanical energy.

A transformer uses the principle of electromagnetic induction to transfer electrical energy between circuits.

An electric motor operates on the principle of electromagnetism, converting electrical energy into mechanical energy.

Bernoulli's principle is represented by the equation P + 1/2 ρv² + ρgh = constant, relating pressure, velocity, and height in a fluid.

The shape of the objects does not affect the gravitational force; only mass and distance do.

The color of the objects does not affect the gravitational force between them.

The length of the specimen does not affect tensile strength; it is an intrinsic property of the material.

Helium behaves most like an ideal gas due to its low intermolecular forces and small size, making it closer to the ideal gas behavior.

At the same temperature, lighter gases have higher average speeds. Hydrogen (H2) has the lowest molar mass and thus the highest average speed.

A diode allows current to flow in one direction only, making it a unidirectional device.

Semiconductors have zero conductivity at absolute zero and their conductivity increases with temperature.

A Zener diode is designed to operate in reverse bias and maintain a constant voltage.

Brittle materials fracture without significant deformation.

Elastic materials return to their original shape after the removal of the applied force.

Nuclear fusion releases energy, requires high temperatures, and occurs in stars, making all options correct.

Nuclear reactions involve large energy changes due to the conversion of mass into energy, unlike chemical reactions.

P-type semiconductors have an excess of holes as majority charge carriers.

Radioactive decay is a random process, meaning that it cannot be predicted when a particular nucleus will decay.

When the object is placed between the focal point and the mirror, the image formed by a concave mirror is virtual and erect.

Photodiodes are commonly used for light detection in various applications.

Transistors are a common application of semiconductors, used in various electronic devices.

Environmental changes can cause variations in measurements, leading to random errors.

Human reaction time can introduce variability in measurements, leading to random errors.