# Search results for query: *

1. ### EMF of a battery and voltmeter

In the last case,when we connect the voltmeters ,my book states that I3=I1+I2 but I am not sure How it came
2. ### EMF of a battery and voltmeter

V1=E- I1R1 V2=E-I2R2 V3=E-I3R3 It's getting bigger to solve as I tried
3. ### EMF of a battery and voltmeter

okay so it makes sense that it shows different readings now...but still How can I proceed if they have different resistance
4. ### EMF of a battery and voltmeter

ideal voltmeter-Which doesn't influence the circuit Real voltmeter-Which has resistance that is not infinitely large Same for battery
5. ### EMF of a battery and voltmeter

Homework Statement We have to measure emf of a battery. We have to voltmeters. Each of them when connected alone across the battery, they read V1 = 0.9V and V2 = 0.6V and when both of them are connected to the battery simultaneously, they both read V3 = 0.45V . What is the emf of battery...
6. ### Current carrying wire

Why don't wires in any circuit touch each other and get short circuited? If two current carrying wires carry charges in same direction then from ampere's law,can't they touch each other due to attractive forces?

Got that
8. ### Stretching of a wire due to it's weight

I have read it sir...I understood that part about the maximum stress
9. ### Stretching of a wire due to it's weight

The tension will be - (mg/L)*x where x is the distance from the bottom Elongation...it should be the force causing the elongation ...in this case the weight so it is (W/AY)dx where dx is the length of the segment
10. ### Stretching of a wire due to it's weight

I think the book considers the bar and wire to be same because they have done the integration using the weight per unit length
11. ### Stretching of a wire due to it's weight

Yep.It's the weight of the bar...I kinda mixed the wire from the first case In the second case,some stress will be acting because the width gets elongated...I have heard that young's modulus makes sense when stress and strain are proportional. In the second case,the wire is acting along the...
12. ### Stretching of a wire due to it's weight

In the second case,the wire gets elongated but the restoring force that is tension remains constant but it;'s width get elongated so will stress also act in that case?
13. ### Stretching of a wire due to it's weight

Makes sense then.So the uppermost point is most probable to break first So the strain will not tell us the condition for breaking but the stress will,right? If the breaking stress is equal to the external force (weight) at the topmost point then beyond this the wire breaks,right? What does...
14. ### Stretching of a wire due to it's weight

Since at the top,the maximum tension acting on is the weight of the wire mg (Why are we calculating this for the upprmost point tho) If at breaking stress,it has to elongate before it breaks then can we use the formulae of strain here maybe
15. ### Stretching of a wire due to it's weight

Since the stress is magnitude of the internal restoring force per unit which in this case is the tension then it will be greatest at the top How exactly did you know to apply the formulae for strain in the second case...I struggled a lot for that My definitions prior to solving a question...
16. ### Stretching of a wire due to it's weight

Homework Statement 1) calculate the longest length of steel wire that can hang vertically without breaking .breaking stress for steel=7.982*10^8N/m^2 and density of steel(d)=8.1*10^3kg/m^3. 2)A bar of mass m and length l is hanging from a point A as shown in the figure.Find the...
17. ### Unpolarised light: Orientation of the E-field

So I can think of unpolarised light as conissting of many polarised lights perpendicular to the direction of wave direction...? Can we do components of these polarised waves in any two perpendiular direction?
18. ### Unpolarised light: Orientation of the E-field

are these wavesof a single light wave or of multiple light waves
19. ### Definition of distance -AR type problem

Looks like I misread the question...my mistake. I think it should be (A) then
20. ### Definition of distance -AR type problem

Dispacement is the vector not distance.It should be (c)
21. ### Unpolarised light: Orientation of the E-field

Homework Statement How does this picture represent a unpolarised light? Homework Equations The Attempt at a Solution [/B] I thought light waves were perpendicular to the direction of propogation so if it has diagonal components then isn't that not perpendicular to the wave direction...
22. ### Direction of electromagnetic field

So by shfting by dt of the magnetic or electric field will tell us the direction
23. ### Direction of electromagnetic field

Is it because of kx+wt or is it part of the question?
24. ### Direction of electromagnetic field

But in my question,why does the wave travel in -x direction
25. ### Direction of electromagnetic field

Homework Statement [/B] In this question, it asks for the magnetic field associated with the electromagnetic wave. Homework Equations The Attempt at a Solution The magnetic field is perpendicular to Electric field but it can be in either x or z direction...how do I choose the direction.I
26. ### Galvanometer sensitivity

Yea.I was actually aiming for that only but later I realized It wasn't going to help me. Thanks for the help
27. ### Galvanometer sensitivity

Okay. The current in the moving coil ammeter is given by S=Ig G/I-Ig Using this ,I calculated the current through the galvanometer which came out to be 11 ig when I plugged S=G/10
28. ### Galvanometer sensitivity

1/4 times the galvanometer resistance in my opinion
29. ### Galvanometer sensitivity

All the major current will flow through the shunt while the same current ig will flow through the galvanometer but my textbook says it will show a deflection of I in this case so I was just confused here. I see now that the sensitivity will get changed due to change in current So here since...
30. ### An Electromagnetic wave goes from air into a medium....

Homework Statement An EM wave from air enters a medium. The electric fields are --> ^ E1 = E01 cos(2πv(z/c-t) x --> ^ E2 =E02cos(k(2z-ct)x in a medium ,where the wave number k and frequency v refer to their value in air.the medium...
31. ### Galvanometer sensitivity

The current through the galvanometer increases and it's value is 11ig(full scale current) tho idk why it gets increases ...? The deflection will be more in the second case
32. ### Galvanometer sensitivity

It starts working as a ammeter
33. ### Galvanometer sensitivity

Homework Statement If a shunt of 1/10th of the coil resistance is applied to a moving coil galvanometer,then it's sensitivity becomes (a)10 fold (b)11 fold (c)1/10 fold (d)1/11 fold Homework Equations ϕ / I = NAB/L The Attempt at a Solution [/B] So sensitivity gets increased by only...
34. ### Potential difference across a resistor

I am getting R=r1-r2
35. ### Potential difference across a resistor

So the potential difference across the interal resistor issame as terminal voltage of the battery?
36. ### Potential difference across a resistor

E-2 E r1 /(R+r1+r2)

E-Ir1
38. ### Potential difference across a resistor

E=2E/(R+r1+r2) r1 But why are solving for the terminal voltage of the battery?

2E/R+r1+r2
40. ### Potential difference across a resistor

Potential difference across r1is Er1/(R+r1+r2) so for zero potential difference r1=0 which looks weird
41. ### Potential difference across a resistor

Homework Statement Two cells of same emf E and different internal resistance r1 and r2 are connected in series to an external resistance R.The value of R for which the potential difference across the first cell is zero is given by (A) R=r1/r2 (B)R=r1+r2 (C)R=r1-r2 (D)R=r1r2 Homework Equations...
42. ### Standing waves in organ pipe

Since the L=5λ/4 and putting λ=1 ,I am gettting 1.25m
43. ### Standing waves in organ pipe

Okay so my length came 1.25 m so what does the extra length tell us?? How should I proceed to do for the water case? Also sorry for my typo...(^|^)
44. ### Standing waves in organ pipe

I am so sorry...it was indeed my mistake
45. ### Standing waves in organ pipe

I made a mess there...only odd values of n will be alllowed there so I should have used a different variable for that I n any case the value of n will be 3 Initially the tube won't be in resonance. (What does this mean)
46. ### Standing waves in organ pipe

Homework Statement In a resonance tube experiment, a closed organ pipe of length 120 cm resonates ,when tuned with a tuning fork of length 120cm resonates,when tuned with a tuning fork of length 340 hz.If water is poured into the pipe ,then (speed of sound in air=340 ms^-1) (A) minimum length...
47. ### Transverse wave on a string

Okay.I got this then Thanx
48. ### Transverse wave on a string

And what does this case look like...are we holding the rope?
49. ### Transverse wave on a string

What is the difference between freely hanging rope and this case? I will keep in mind to mention the units next time .
50. ### Transverse wave on a string

Change in tension in a rope having masses incrases linearly throughout the rope