Answer:
66.98 db
Explanation:
We know that

L_T= Total signal level in db
n= number of sources
L_S= signal level from signal source.

= 66.98 db
Answer:
Total energy saving will be 0.8 KWH
Explanation:
We have given there are 50 long light bulbs of power 100 W so total power of 50 bulb = 100×50 = 5000 W = 5 KW
30 bulbs are of power 60 W
So total power of 30 bulbs = 30×60 = 1800 W = 1.8 KW
Total power of 80 bulbs = 1.8+5 = 6.8 KW
Total time = 3 hour
We know that energy 
Now power of each CFL bulb = 25 W
So power of 80 bulbs = 80×25 = 2000 W = 2 KW
Energy of 80 bulbs = 2×3 = 6 KWH
So total energy saving = 6.8-6 = 0.8 KWH
Answer:
e) electrons are transferred from the rod to the silk.
Explanation:
An initially neutral glass rod contains equal number of electron and proton.
If the rod becomes positively charged after being rubbed with silk, then the rod must have lost some its electron to the silk since electrons are more mobile than protons, leaving the rod with excess positive charge (protons), and the silk will be negatively charged (excess electron).
Thus, the rod becomes positively charged by transfer of electrons from rod to the silk.
e) electrons are transferred from the rod to the silk.
Answer:
i hope this will help you :)
Explanation:
mass=19kg
density=800kg/m³
volume=?
as we know that
density=mass/volume
density×volume=mass
volume=mass/density
putting the values
volume=19kg/800kg/m³
so volume=0.02375≈0.02m³