# Search results

1. ### Force required to keep a wooden block from sliding on a rough incline

@Doc Al It's actually a Test prep book published by a very well known publisher in my country at least . This question was part of the actual test held in 2012 . The question goes like The minimum force required to move a body up an inclined plane is three times the minimum force required to...
2. ### Force required to keep a wooden block from sliding on a rough incline

Homework Statement This thing was a part of an entire question . I solved the other parts but I don't know why I am messing up here . Force required to keep a wooden block from sliding on a rough incline with coefficient of friction μ Homework Equations Force on a block on an...
3. ### Matrix and inverse matrix question?

How did I miss that . Thanks
4. ### Matrix and inverse matrix question?

Homework Statement how do I solve this question https://www.dropbox.com/s/bn958xnm5483s6u/photo%20%281%29.JPG (This link if the image is not visible : https://www.dropbox.com/s/bn958xnm5483s6u/photo%20%281%29.JPG) just so the equation is not clear it says A2 = λA - 2I The inverse should be...
5. ### Probability question regarding independent events, where am I wrong ?

Homework Statement E1 and E2 are two independent events. The probabilities of an error in judgement by a person regarding E1 and E2 are 0.02 and 0.05 respectively. Find the probability that the person will take the correct decision regarding : only one event Homework Equations Two events...
6. ### To prove that vectors (a + b) . (a - b) = a^2 + b^2 iff

@Pranav The question is correct
7. ### To prove that vectors (a + b) . (a - b) = a^2 + b^2 iff

Homework Statement The question says : Prove that (\vec{a} + \vec{b}).(\vec{a} - \vec{b}) = \left | \vec{a} \right |^{2} + \left | \vec{b} \right |^{2} if and only if \vec{a} \perp \vec{b} Homework Equations This is known that \left | \vec{a} + \vec{b} \right | = \left | \vec{a} -...
8. ### Estimate the number of electrons flowing in a semiconductor pn junction

Homework Statement The drift current in a p-n junction is 20μA . Estimate the number of electrons crossing a cross section per second in the depletion region. Homework Equations Drift current is the current that occurs due to formation of holes and electrons in the depleted region from...
9. ### [Ma4b2] Isomerism in coordinate complexes cofusion

Bummer! should've had checked once, yea they are the same.
10. ### [Ma4b2] Isomerism in coordinate complexes cofusion

Consider a complex with Central Metal atom M A and B are monodentate ligands . Consider a compound with formula as [M A4 B2] . Textbook and the web says there can be only 2 possible isomers of this compound . What I say is, why can't I in the first image put A on the top and bring B...
11. ### Can a volume of gas exert pressure on itself ?

Thanks everyone I got it finally !
12. ### Can a volume of gas exert pressure on itself ?

So, I was going through the solved problem sets and encountered this question which is to find the relation between two ends of a cylinder filled with gas rotating about a vertical axis fixed at one end (the red axis) . I understood the solution but there is one thing still confusing me...
13. ### Difference between ionic and molar conductivity ? (Electrochemistry)?

So,Activity is the effective concentration - i.e. that portion of the ions which are free to take part in a given reaction - It becomes proportionately less as the concentration increases. So that means if I increase concentration number of ions taking part in electrical conductivity decreases...
14. ### Difference between ionic and molar conductivity ? (Electrochemistry)?

That's called the Cell constant. Cell constant = l / A l is the distance between the electrodes and A is the area of the electrodes . I am still confused here, how come the conductivity decreases on decreasing concentration but molar conductivity increases ? Looking forward to a...
15. ### Difference between ionic and molar conductivity ? (Electrochemistry)?

@Borek I am a little confused here, Heres what my textbook says "Conductivity always decreases with decrease in concentration of both strong and weak electrolytes.This can be explained by the fact that the number of ions per unit volume that carry the current decreases on dilution" Now...
16. ### Difference between ionic and molar conductivity ? (Electrochemistry)?

But the formula Molar conductivity = specific conductivity /Concentration Suggests that molar conductivity should decrease with increase in concentration ..
17. ### Difference between ionic and molar conductivity ? (Electrochemistry)?

The more concentrated the solution is the more number of ions are present in the solution so the conductivity should increase, is this reasoning wrong?
18. ### Difference between ionic and molar conductivity ? (Electrochemistry)?

What I know is Molar conductivity is The conductivity of the elctrolyte divided by its concentration . Can someone please explain the physical significance of this ? Also ionic conductivity depends on concentration, if I dilute the electrolyte the ionic conductivity decreases but Molar...
19. ### Why in a LC circuit does the current reverse ?

So I was learning about the LC circuit and I know that an inductor would oppose the change in current through it, so if I connect a charged capacitor with an inductor, the charges on the capacitor would want to flow to the other side and neutralize the two plates like it does when the two plates...
20. ### Potential energy and kinetic energy of a revolving object like moon. Whats there role

Cannot understand this , would mind explaining it once?
21. ### Potential energy and kinetic energy of a revolving object like moon. Whats there role

So if I use energy equal to the potential energy , will I be able to remove the moon?(Sounds like some evil plan LOL)also if I consider potential energy to be 0 how would it affect the energy required to remove the moon?
22. ### Photon emitted by a hydrogen atom in Lyman series and Balmer series at once ?

Homework Statement Whenever a photon is emitted by hydrogen atom in the Balmer series, it is followed by a photon in Lyman series . What wavelength does this latter photon correspond to ? Homework Equations Balmer series corresponds to the wavelengths in the visible spectrum and Lyman...
23. ### Potential energy and kinetic energy of a revolving object like moon. Whats there role

So lets consider the moon its rotating around the earth in a fixed orbit, its moving at a velocity say v so it possess a kinetic energy 1/2 mv2 . the gravitational force between the earth and the moon is also present which attracts the moon towards the earth . My question is does the moon has a...
24. ### Potential Energy of hydrogen atom in ground state is 0, find energy in 1st exc state

Yeah it isn't In the E e^2 should be e^4 And in velocity pi should be replaced by epsilon I posted this from my phone .My bad
25. ### Potential Energy of hydrogen atom in ground state is 0, find energy in 1st exc state

oops! 10.2eV is required to excite the electron from the ground to the first excited state.
26. ### Potential Energy of hydrogen atom in ground state is 0, find energy in 1st exc state

Homework Statement What is the energy of H atom in the first excited state if the potential energy in the ground state is taken to be 0 ? Homework Equations Usually the energy of H atom in the ground state is -13.6eV and in the 1st excited state is -10.2eV E(n) = πme2/8ε2h2 Bohr's...
27. ### Find the number of fringes that will shift in young's double slit experiment

Homework Statement Monochromatic light of wavelength 600nm is used in a young's 'double slit experiment . One of the slits is covered with a thin transparent layer (1.8 * 10^-9m ) made of a material of refractive index n(1.6). How many fringes will shift due to the introduction of the...
28. ### Need a little intuition on equation of travelling wave .

So heres the equation y(x,t) = A cos (kx - wt) where A is the amplitude of vibration and k = 2pi/lambda i have already dealt with SHM or SHO and i completely understand the equations like x = Acos(wt + phi) but i didnt really dealt with waves and the equation of travelling wave is kinda...
29. ### Chemical Kinetics Question . Determination of order of reaction

Homework Statement So the question says for the reaction 2N2O5(g) --> 4NO2 (g) + O2(g) provides a linear plot when P(N205) is plotted against t with a negative slope . The decomposition of N2O5 follows ? Homework Equations The Attempt at a Solution I am guessing that P(N205) is...
30. ### The Modulus function . Need a little Explanation

So I have been dealing with the modulus function for almost a year now , I didn't ran into it many times so didn't really tried to understand it well . But it has started to get a little bit confusing . So if someone helps me I will be really happy . From what I know f(x) = |x| = { x ; x >=...