12 V is the f.e.m.

of the battery. The potential difference that is applied to the motor is actually the fem minus the voltage drop on the internal resistance r:

this is equal to the voltage drop on the resistance of the motor R:

so we can write:

and using

and

we can find the current I:
The cutoff frequency for magnesium is 8.93 x 10¹⁴ Hz.
<h3>What is cutoff frequency?</h3>
The work function is related to the frequency as
W0 = h x fo
where, fo = cutoff frequency and h is the Planck's constant
Given is the work function for magnesium is 3.70 eV.
fo = 3.7 x 1.6 x 10⁻¹⁹ / 6.626 x 10⁻³⁴
fo = 8.93 x 10¹⁴ Hz.
Thus, the cut off frequency is 8.93 x 10¹⁴ Hz.
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Test questions measure recall; matching concepts with their definitions measures recognition.
<u>Explanation:
</u>
According to Psychology our brain remembers everything what we learn but the understanding and remembering the right answer for the right question needs training and understanding ability. So in order to enhance the ability of recalling and recognizing among the students, the concept of test questions and matching with definitions are used in curricular activities.
As the students will be learning different terms, definitions, methods and different subjects, they should be able to distinguish among different definitions as well as they should recall the things they have learnt. So the answers for the test questions will help to recall the topics learnt by the students while the matching concept will help the students to recognize each definition with their terms.
a compound microscope is used for viewing samples at high magnification<span> 40 - 1000x, which is achieved by the combined effect of two sets of lenses: the ocular lens in the eyepiece and the objective lenses close to the sample.</span>
The distance from the horizontal top surface of the cube to the water level is "6.282 cm".
<h3>What is Archimedes' principle?</h3>
According to Archimedes' principle, the weight of the fluid that the body displaces is equal to the upward buoyant force that is applied to a body submerged in a fluid, whether fully or partially. The Archimedes' principle is a fundamental physical law in fluid mechanics. It was created by Syracuse's Archimedes.
According to Archimedes' principle, a body submerged in a fluid experiences an upward force proportional to the weight of the fluid that has been displaced. One of the prerequisites for equilibrium is this. We believe that the buoyancy force, also known as the centre of buoyancy, is situated in the middle of the submerged hull.
From Archimedes' principle, we get



=11.72cm
So,
The distance from horizontal top to the water level will be:
=18-11.72
=6.282cm
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