Answer:
Tungsten wire is used as the filament in light bulbs. It glows white-hot as current passes through it.
Tungsten is used in light bulbs because its high <u>RESISTANCE</u> converts electric energy into light and heat.
Explanation:
Answer:
The farther star will appear 4 times fainter than the star that is near to the observer.
Explanation:
Since it is given that the luminosity of the 2 stars is same thus they radiate the same energy per unit time
Consider a spherical wave front of energy 'E' that leaves both the stars (Both radiate 'E' as they have same luminosity)
This Energy is spread over the whole surface area of sphere Thus when the wave front is at a distance 'r' the energy per unit surface area is given by

For the star that is twice away from the earth the distance is '2r' thus we will receive an energy given by
Hence we sense it as 4 times fainter than the nearer star.
Answer:
The wavelength can always be determined by measuring the distance between any two corresponding points on adjacent waves. In the case of a longitudinal wave, a wavelength measurement is made by measuring the distance from a compression to the next compression or from a rarefaction to the next rarefaction.
Explanation:
Answer:
Explanation:
- For diagram refer the attachment.
It is given that five cells of 2V are connected in series, so total voltage of the battery:

Three resistor of 5
, 10
, 15
are connected in Series, so the net resistance:



According to ohm's law:


On substituting resultant voltage (V) as 10 V and resultant resistant, as 30
we get:


The electric current passing through the above circuit when the key is closed will be <u>0.33 A</u>