C++ | MCQs

Explanation

In the C.G.S system (Centimeter-Gram-Second), the unit of mass is gram.

This system uses centimeter for length and second for time.

Explanation

Inner Solar System:

Includes the four rocky planets:

Mercury, Venus, Earth, Mars

These are closer to the Sun, have solid surfaces, and are also called terrestrial planets.

Outer Solar System:

Includes the gas giants and ice giants:

Jupiter, Saturn, Uranus, Neptune

These planets are larger, farther from the Sun, and composed mostly of gas or ice.

So, Jupiter is not part of the inner solar system.

Explanation

Earth, Mars, and Pluto have atmospheres that contain Nitrogen gas.

• Earth: ~78% nitrogen
• Mars: ~2.6% nitrogen
• Pluto: thin atmosphere with nitrogen ice and gas

Neptune's atmosphere is mostly hydrogen, helium, and methane, not nitrogen.

Explanation

Escape velocity depends on the mass and radius of a planet.  

   - Mercury has the lowest mass and smallest radius, hence the least escape velocity.  

Explanation

Electric Flux Maximum (Φ = E·A·cosθ)  

   - When the area vector is perpendicular to the electric field, θ = 0°, so cosθ = 1.  

   - Therefore, Φ = EA (maximum possible flux). 

Explanation

One up quark and two down quarks, when combined, make a neutron. 

More specifically:

A proton consists of two up quarks and one down quark (uud). 

A neutron consists of one up quark and two down quarks (udd). 

An electron and a positron are elementary particles, not composed of quarks. 

Explanation

- Capacitance with dielectric: C = εr · C₀, where C₀ is the capacitance without dielectric.

- If the dielectric is removed, capacitance becomes C₀ = C / εr. 

So, the new capacitance is C divided by εr.

Explanation

According to Raoult's Law, the relative lowering of vapor pressure for a solution is equal to the mole fraction of the solute. 

Raoult's Law states that the vapor pressure of a solvent in a solution is equal to the vapor pressure of the pure solvent multiplied by its mole fraction in the solution.

Therefore, the relative lowering of vapor pressure, which is the difference between the vapor pressure of the pure solvent and the vapor pressure of the solution, is directly proportional to the mole fraction of the solute. 

Explanation

If the force acting on a body is plotted along the y-axis and the displacement covered as a result is plotted along the x-axis, then the work done is given by the Area under the curve.

Explanation

In simple harmonic motion (S.H.M), the restoring force is minimum at Mean position. 

The restoring force is directly proportional to the displacement from the mean position.

At the mean position, the displacement is zero, meaning the restoring force is also zero at that point.