Jnu 2013 Definition and 13 Threads

Homework Statement Homework EquationsThe Attempt at a Solution As frequency is decreased to threshold, no. of emitted electrons will remain same, but their maximum kinetic energy will decrease. So, the current should decrease slowly. For frequency less than the threshold frequency, no...

Homework Statement Homework EquationsThe Attempt at a Solution The probability of getting a state with energy ## E_v## is ## \frac { N_v } { N_v +N_c } = \frac1{ e^{-(E_v – E_f)/k_BT} +1} ## ………….(1) Since, ## E_v < E_f, e^{-(E_v – E_f)/k_BT}>>1 ## as ## E_f – E_v>> k_BT ##……….(2) So...

Homework Statement Homework EquationsThe Attempt at a Solution Using ## \nabla \times \vec A = \vec B##. I got that both ##\v A_1 ~~and~~ \vec A_2 ## produce ## \vec B##. So, the correct option is (d). Is this correct? [/B]

Homework Statement Homework EquationsThe Attempt at a Solution [/B] The thing to remember is that inside the Earth surface, the gravitational field does not remain inversely proportional to ##r^2##. The equation of motion is ## \ddot r = \frac { -gr} R## ....(1) This means that the...

Homework Statement Homework EquationsThe Attempt at a Solution From the equation it is clear that the wave is propagating in y direction. So, the magnetic field is along z- axis. ……….(1) Dimensionally B = E/v……….(2) According to the above two conditions , the correct option is (c). Is this...

Homework Statement Homework EquationsThe Attempt at a Solution I will try to choose the correct option using the common sense instead of solving it. As d decreases, the flux should increase. For R>>d, only option (a) and (d) satisfy this condition. Now, for choosing between (a) and (d)...

Homework Statement Homework EquationsThe Attempt at a Solution The energy stored in the capacitor is ## \frac { CV^2 } { 2 }##. So, this much energy will dissipate as heat. Hence, the correct option is (a). Is this correct? It doesn't depend on the shape of the capacitor, right? I have...

Homework Statement Homework EquationsThe Attempt at a Solution E = (13.6 – 3.4 = 10.2)eV = ## \frac {hc } { \lambda } ## =1.22 * 10^{-5} cm So, the correct option is (a). Is this correct?

Homework Statement Homework EquationsThe Attempt at a Solution I think that ## \frac { \sin \theta } {\sin \theta ' } = \frac { n_2} { n_1} ## I am taking the dielectric constant as 1 as the potential is 0 i.e. the medium is air.. So, ##n_1 = 1## For the 2nd medium, The dielectric...

Homework Statement Homework EquationsThe Attempt at a Solution ## dS = \frac { dQ_{rev} } { T } ## Assuming that isothermal process is a reversible processes, ## dU = dQ – pdV## For isothermal process, dU = 0. ## dQ = pdV ## ## pV = nRT##, where n is number of moles. For one mole, ##...

Homework Statement Homework EquationsThe Attempt at a Solution [/B] I am taking the free energy as the internal energy of the ideal gas. Then the average internal energy per unit volume is ## \frac { 3 nk_B T } {2 } ##. So, the correct option is (c). Is this correct?

Homework Statement Homework EquationsThe Attempt at a SolutionChemical potential is defined as ## \mu = Gibbs potential per particle ##. So, is the system consists of N particles, ##\mu = \frac { G } {N } ##. Now, dG = VdP – SdT ## \frac {dG } { N } = \frac { VdP } { N } - \frac { SdT }...

Homework Statement Homework EquationsThe Attempt at a Solution Let's say that the last carriage gets uncoupled at time t = 0s and at this time the train has moved a distance ##l_0##.The resistive force could be given as ## F_r = AM##, where A is the appropriate constant and M is the mass of...