A photoelectric cell is an electronic device which is used to convert light energy into electric energy.The operation of this device is based on photoelectric effect.
Light of suitable frequency i.e greater or equal to threshold frequency will fall on the cathode maintained at negative potential.The electron emission will take place and these electrons are drifted towards the anode which is at positive potential.
Here,only those radiations will be capable of emitting electrons irrespective of surface barrier of metals whose energy is greater than the work function.
We know that the radiation having long wavelength has least energy as energy and wavelength are inversely proportional to each other.
Here h is the Planck's constant,c is the velocity of light.
Here we have been given red light and blue light.
In the visible spectrum of radiation, the red light has longer wavelength than all other colors of light.Hence blue light has more energy as it's wavelength is less as compared to red light.
Hence, the blue light will activate the most and red the least.
Answer:
the required mass flow rate is 49484.37 kg/s
Explanation:
Given the data in the question;
we first determine the relation for mass flow rate of water that passes through the turbine;
so the relation for net work on the turbine due to the change in potential energy considering 100% efficiency is;
= m ( Δ P.E )
so we substitute (gh) for ( Δ P.E );
= m (gh)
m = / gh
so we substitute our given values into the equation
m = 100 MW / ( 9.81 m/s²) × 206 m
m = ( 100 MW × 10⁶W/MW) / ( 9.81 m/s²) × 206 m
m = 10 × 10⁷ / 2020.86
m = 49484.37 kg/s
Therefore, the required mass flow rate is 49484.37 kg/s
Answer:
The amount of charge the space shuttle collects is -1.224nC
Explanation:
The magnitude of Electric potential is given as;
V = kq/r
where;
V is the electric potential in volts
k is coulomb's constant
r is the radius of the sphere or distance moved by the charge
given; V = -1.1 V, k = 8.99 x 10⁹ Nm²/C², r = 10m
Substituting this values in the above equation, we estimate the amount of charge space shuttle collects.
q = (V*r)/k
q = (-1.1 *10)/(8.99 x 10⁹ )
q = -1.224 X 10⁻⁹ C
q = -1.224nC
Therefore, the amount of charge the space shuttle collects is -1.224nC
Answer:
T = 686.7N
Explanation:
For this exercise we will use Newton's second law in this case there is no acceleration,
∑ F = ma
T -W = 0
The gymnast's weight is
W = mg
We clear and calculate the tension
T = mg
T = 70 9.81
T = 686.7N
