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.
Fast Communication, can be used for good and can be used for bad hackers.
Answer:
Explanation:
Given
Weight of person
At highest point Magnitude of the normal force
net force at highest point
where
centripetal force
Normal Force
Negative sign shows force is in upward direction
At bottom point centripetal force is towards the bottom
Answer:
We know the information about atomic size, energy, electronic configuration etc. of atom from the periodic table.
Explanation:
- Periodic table is the arrangement of elements that are arranged according to their properties and electronic configuration.
- In periodic table, on furthest right side of the periodic table, noble gases like He, Ne, Ar etc are arranged.
- The atomic number of element increases while moving from left towards right in the periodic table.
- The metallic character of element decreases as we proceed the table towards right.
- They readily accept electron to fill the valence shell hence becoming more metallic in character.
Answer:
Magnitude of the magnetic field inside the solenoid near its centre is 1.293 x 10⁻³ T
Explanation:
Given;
number of turns of solenoid, N = 269 turn
length of the solenoid, L = 102 cm = 1.02 m
radius of the solenoid, r = 2.3 cm = 0.023 m
current in the solenoid, I = 3.9 A
Magnitude of the magnetic field inside the solenoid near its centre is calculated as;

Where;
μ₀ is permeability of free space = 4π x 10⁻⁷ m/A

Therefore, magnitude of the magnetic field inside the solenoid near its centre is 1.293 x 10⁻³ T