Answer:
Infinite Distance
Explanation:
The electric potential due to a point charge can be expressed by the following equation:
Here,
V is the electric potential due to the point charge
k is the proportionality constant
Q is the magnitude of the point charge
r is the distance from the charge
As the value of r increases, the value of V decreases since there is an inverse relation between the two. The value of V can be absolutely 0 when the distance from the charge is infinite i.e. r is infinite. Mathematically, dividing a number by infinity results in zero. Also theoretically speaking, at infinite distance the electric field lines won't approach and hence the electric potential would be zero.
Given :
Whole-body dose of 8.4 mGy from gamma-rays and 1.2 mGy from 80-Kev neutrons.
To Find :
The effective dose to a worker.
Solution :
By the given information effective dose to a worker is given by :
E.D = ( 8.4 × 1.2 × 0.12 ) + ( 1.2 × 1 × 1 )
E.D = 1.2096 + 1.2
E.D = 2.4096
Therefore, the effective dose to a worker is 2.4096 .
Answer:
This is an incomplete question. The complete question is --
An individual white LED (light-emitting diode) has an efficiency of 20% and uses 1.0 W of electric power.
How many LEDs must be combined into one light source to give a total of 3.8W of visible-light output (comparable to the light output of a 100W incandescent bulb)?
And the answer is --
19 LEDs
Explanation:
The full form of LED is Light emitting diode.
It is given that the efficiency of the LED bulb is 20 %
1 LED uses power = 1 W
So the output power of 1 LED = 0.2 W
We need to find the power required to give a 3.8 W light.
Power required for 3.8 W = Number of LEDs required = (total required power / power required for 1 LED )
= 3.8 / 0.2
= 19
Therefore, the number of LEDs required is 19.
Answer:
Explanation:
Given
Distance of target d=75 m
velocity of bullet v=250 m/s
First taking horizontal motion
as there is no acceleration is horizontal direction therefore 
where u=initial velocity
=acceleration
t=time
In this time Vertical distance moved by Bullet is
here 
