Work Energy And Power

The energy level of a certain atom for 1^st 2^nd and 3^rd levels are 2E, respectively. If A and A be the wavelengths of emitted photon for 3→1 and 2 →1 transition respectively, then is

represents a moving pulse where x and y are in metre and t is in second. Then

The second overtone of an open organ pipe has the same frequency as the first overtone of a closed pipe of length L. The length of the open pipe will be

When a spring is stretched by x amount, the potential energy stored in it is E. When the spring is stretched by another x amount, the potential energy stored in the spring becomes E'. Then is,

Two different coils have self-inductances L₁ = 8 mH and L₂ = 2 mH. Currents in both coils are increased at a same constant rate. Also, at a certain instant, the powers given to the two coils are same. If I₁, V₁, U₁ and I₂, V₂, U₂ represent the current, the induced voltage and the energy stored in the first coil and in the second coil respectively at any particular instant, then which of the following is/are correct?

An electron of mass m and a photon have same energy E. If their de Broglie wavelengths are and , respectively, then is proportional to,