Physics: Post your doubts here!

[Kanekii]

C?

what is thissss explainnnnnn

 

[bacon byun]

A vibrating tuning fork is held above a glass cylinder filled to the top with water. The water level is
steadily lowered. A loud sound is first heard when the water level is 83.5 cm above the bench.
The next loud sound is heard when the water level is 17.1 cm above the bench.

The speed of sound in air is 340 m s–1.
What is the frequency of the tuning fork?
A 128 Hz B 256 Hz C 384 Hz D 512 Hz

please explain this question.

 

[A*****]

helpaaa

This is the stationary wave formed....before this those formed were not given in the options so this is corect

 

[Kanekii]

A vibrating tuning fork is held above a glass cylinder filled to the top with water. The water level is
steadily lowered. A loud sound is first heard when the water level is 83.5 cm above the bench.
The next loud sound is heard when the water level is 17.1 cm above the bench.

The speed of sound in air is 340 m s–1.
What is the frequency of the tuning fork?
A 128 Hz B 256 Hz C 384 Hz D 512 Hz

please explain this question.

Wavelength= 83.5-17.1*(2)
Wavelength=1.33m
V=f*wavelength
F=V/wavelength
F=340/1.33
F=256Hz

 

[A*****]

what is thissss explainnnnnn

When the current is zero, the voltage corresponds to the emf of the cell
Since it is decreased, so the intercept will be lower, ruling out A and C
V/I is internal resistance of battery which has increased so the gradient of new graph will increase, making the answer B

 

[A*****]

somebody solve thistoo plssss

For destructive interference the path difference is 0.5λ, 1.5λ, 2.5λ, etc. For the first dark fringe i.e. n=1, it is 0.5λ so if u put the value of n in the C option so you will find that the p.d is 0.5λ, hence C is correct

 

[Kanekii]

For destructive interference the path difference is 0.5λ, 1.5λ, 2.5λ, etc. For the first dark fringe i.e. n=1, it is 0.5λ so if u put the value of n in the C option so you will find that the p.d is 0.5λ, hence C is correct

But shouldnt it be D as it asks only for positive values of n

 

[A*****]

But shouldnt it be D as it asks only for positive values of n

1 is a positive value of n...but if we use D for the 1st dark fringe, the path diff would be 1.5λ which is not correct...it should be 0.5λ

 

[Kanekii]

1 is a positive value of n...but if we use D for the 1st dark fringe, the path diff would be 1.5λ which is not correct...it should be 0.5λ

Oh i see!

 

[khadijaimran]

This is the stationary wave formed....before this those formed were not given in the options so this is corect
View attachment 64129

how did you know you have to make a stationary wave like this with 4 nodes?

 

[Hisham Khan]

NERDS!

 

[Tom Sewage]

Hi
need help, pls can someone explain me how to solve these questions
the answer are
27 C
28 D

 

[Canttouchthis]

D?

I thot it was d 2 but its actually c wtf

 

[Canttouchthis]

C?

that one is b
I am so dead for tomrrw
helppp

 

[Kanekii]

how did you know you have to make a stationary wave like this with 4 nodes?

Since the tube is open at both ends antinode will be formed at each end. For this you will have to figure out different combinations of wavelength from the fundamental frequency

 

[Canttouchthis]

When the current is zero, the voltage corresponds to the emf of the cell
Since it is decreased, so the intercept will be lower, ruling out A and C
V/I is internal resistance of battery which has increased so the gradient of new graph will increase, making the answer B

sick, thanks

 

[Kanekii]

that one is b
I am so dead for tomrrw
helppp

Sem here, i just hate waves its drawing and etc i just haige if

 

[Canttouchthis]

This is the stationary wave formed....before this those formed were not given in the options so this is corect
View attachment 64129

don't get this one
why is length=2wavelenth??

 

[Canttouchthis]

For destructive interference the path difference is 0.5λ, 1.5λ, 2.5λ, etc. For the first dark fringe i.e. n=1, it is 0.5λ so if u put the value of n in the C option so you will find that the p.d is 0.5λ, hence C is correct

genius, thanks again

 

[hellodjfos;s'ff]

View attachment 64130

View attachment 64131

Hi
need help, pls can someone explain me how to solve these questions
the answer are
27 C
28 D

27: The formula for path difference is (n-1/2)lamda
n=2, and you can find lamda using x=lamda(D)/a (the double slit formula)
Your lamda will turn out to be 4x10^-9 m
Now just insert the n and lamda into the path difference equation: (2-0.5)(4x10^-7)
Ans will be option C

28: For open tube/pipe, formula for lowest frequency is f=v/2L
v=fx(2L) ---- your open tube equation
For closed tube, formula for lowest frequency is: f=v/4L
v=fy(8L) ----- your closed tube equation
Solve the two equations algebraically now
fx(2L)=fy(8L)
fx=4Fy(D)