Learn 94 questions from Station Officer (Fire and Rescue Services)

Station Officer (Fire and Rescue Services) Questions

The larval stages of sponges include: 
Planula: A free-swimming, ciliated larval organism that results from multiple cell divisions of a zygote 
Amphiblastula: A common larval stage found in scypha 
Parenchymula: A common larval stage found in leucosolenia 
Sponges have a life cycle that includes a vegetative growth phase, gemmulation (asexual reproduction), sexual reproduction, cryptobiosis (resting phase), gemmule hatching, and regeneration. If sexual reproduction occurs, parenchymella larvae are produced and disperse before developing into a mature sponge.

Semi conservative mode of DNA replication

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<li>Nuclear fusion, the source of all the energy so generously radiated by the Sun, does two things: it converts hydrogen into helium (or rather, makes helium nuclei from protons) and it converts mass to energy.</li>
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<p style="color: rgb(255,255,255);">&nbsp;</p>
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<li>The CNO cycle (for carbon–nitrogen–oxygen) is one of the two known sets of fusion reactions by which stars convert hydrogen to helium, the other being the proton–proton chain reaction (pp-chain reaction)</li>
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<p style="color: rgb(255,255,255);">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;So statement is true</p>
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<div>Gases can be liquefied by applying pressure at suitable temperature.</div>
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<div>&nbsp;But, as the temperature increases, there is an increase in kinetic energy of the molecules of gas. This makes the process of liquefication of gas very difficult. So, critical temperature is the temperature above which, gas cannot be liquefied.</div>
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<div>Easily liquefiable gases have high critical temperature because, there is more forces of attraction among the molecules, which require a large temperature to go apart and lose contact, thus, they have high critical temperature.</div>
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<p style="padding-left: 40px; color: rgb(255,255,255);"><strong>Stress = (weight of wire) / Area</strong></p>
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<li>Stress - σ</li>
<li>weight of wire - mg</li>
<li>Area - A</li>
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<p style="padding-left: 40px; color: rgb(255,255,255);"><strong>density = mass/volume</strong></p>
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<li>ρ = m/V</li>
<li>So, m = ρV</li>
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<p style="padding-left: 40px; color: rgb(255,255,255);"><strong>Substituting these values in stress equation,</strong></p>
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<li>σ = (mg)/A</li>
<li>σ = (ρVg)/A</li>
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<p style="padding-left: 40px; color: rgb(255,255,255);"><strong>Volume = Area x Height</strong></p>
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<li>V = A x h</li>
<li>σ = (ρVg)/A</li>
<li>σ = (ρAhg)/A</li>
<li>σ = ρhg</li>
</ul>
<p style="padding-left: 40px; color: rgb(255,255,255);"><strong>Rearranging this equation, we get</strong></p>
<p style="padding-left: 40px; color: rgb(255,255,255);"><strong>h = σ/ρg</strong></p>
<p style="padding-left: 40px; color: rgb(255,255,255);">Where, h indicates the greatest length of the wire that can hang freely without breaking.</p>
<p style="padding-left: 40px; color: rgb(255,255,255);">&nbsp;</p>
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<p style="padding-left: 40px; color: rgb(255,255,255);">&nbsp;</p>
<p style="padding-left: 40px; color: rgb(255,255,255);">&nbsp;</p>

The radius of the innermost electron orbit of a hydrogen atom is 5.3×10⁻¹¹ m.

both differentiable and continuous at x = 0

continuous but not differentiable at x = 0

differentiable but not continuous at x = 0

neither differentiable nor continuous at x = 0

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