Using the Planck's Equation, comes:

If you notice any mistake in my english, please let me know, because i am not native.
So, a concave mirror is a mirror that goes inward, thus, making a convex mirror have an outward curvature. Ex: A convex mirror is used at the front of a bus.
Answer:
the definition of civics is the study of the rights and duties of citizenship.
so the answer is B.
hope this helps.
Answer:
Wind turbines operate on a simple principle. The energy in the wind turns two or three propeller-like blades around a rotor. The rotor is connected to the main shaft, which spins a generator to create electricity.
Explanation:
Answer: 
Energy is directly proportional to the frequency.
The energy of a photon is given by:

Where, E is the energy and
is the frequency.
Frequency of the radio wave is given:


Multiply the above two:
Energy,

Hence, the energy of each photon of radio wave having frequency
is 