Answer:
The peak value of the electric field is 489.64 V/m
Explanation:
Given;
power of the laser, P = 1.0 mW = 1 x 10⁻³ W
Radius of the beam, R = 1.0 mm = 1 x 10⁻³ m
Area of the beam = πr² = π(1 x 10⁻³ )² = 3.142 x 10⁻⁶ m²
The average intensity of the light = P / A
The average intensity of the light = ( 1 x 10⁻³) / (3.142 x 10⁻⁶)
The average intensity of the light = 318.27 W/m²
The peak value of the electric field is given by;
Therefore, the peak value of the electric field is 489.64 V/m.
Answer:
Explanation:
Given that,
The energy of the microwave oven is .
We need to find the wavelength of these photons.
The energy of a wave is given by :
Put all the values,
So, the wavelength of these photon is .
Given:
The thermal energy added to the system is Q = 90 J
The work done by the system on the surroundings is W = 30 J
To find the change in internal energy.
Explanation:
According to the first law of thermodynamics, the change in internal energy can be calculated by the formula
On substituting the values, the change in internal energy will be
Final Answer: The chage in internal energy is 60 J (option D)