Using lens equation;
1/o + 1/i = 1/f; where o = Object distance, i = image distance (normally negative), f = focal length (normally negative)
Substituting;
1/o + 1/-30 = 1/-43 => 1/o = -1/43 + 1/30 = 0.01 => o = 1/0.01 = 99.23 cm
Therefore, the object should be place 99.23 cm from the lens.
Answer:
<h3>
The charge transferred from the cloud to earth is 1 Coulomb.</h3>
Explanation:
Given :
Current
A
Time
sec
We know that the current is the rate of flow of charge.
From the formula of current,
<h3>

</h3>
Where
charge transfer between cloud and earth.


C
Hence, the charge transferred from the cloud to earth is 1 Coulomb.
Answer:
When we talk about residential uses of energy, these are the most basic uses of energy . They include watching television, washing clothes, heating and lighting at home , taking a shower, working from home on your laptop or computer, running appliances and cooking.
Answer:
B. Maximum velocity of ejected electrons.
Explanation:
The ejection of electrons form a metal surface when the metal surface is exposed to a monochromatic electromagnetic wave of sufficiently short wavelength or higher frequency (or equivalently, above a threshold frequency), which leads to the enough energy of the wave to incident and get absorbed to the exposed surface emits electrons. This phenomenon is known as the photoelectric effect or photo-emission.
The minimum amount of energy required by a metal surface to eject an electron from its surface is called work function of metal surface.
The electrons thus emitted are called photo-electrons.
The current produced as a result is called photo electricity.
Energy of photon is given by:

where:
h = Planck's constant
frequency of the incident radiation.