As physics p1 MCQS YEARLY ONLY.

[Adira Luis]

Sis I said, I have only this way, Hadi has other way... he'll help you

there is something called as explaining your way?

 

[Thought blocker]

there is something called as explaining your way?

Sorry sis, I am in the car so typing slow... Going to school
So Here we use the equation - Kinematics eqution - V^2 = U^2 + 2as
As we wanna know the value of v / u this is the only equation which covers our information asked in question...
So when the sphere hits the plate V = 0 and u=u
so we can write that as 0 = u^2 + 2ah taking downwards direction as +ve direction ; that means u^2 = -2ah
And when the ball rebounds, u = 0 and v = v and height is halved.
so , v^2 = 0 + 2(-a)(h/2) = -ah as 2 and 2 gets canceled
so divide v^2 / u^2
= -ah / -2ah = 1 / 2
taking root on R.H.S will remove squares from L.H.S
so,
v/ u = 1 / root 2

 

[Adira Luis]

Sorry sis, I am in the car so typing slow... Going to school
So Here we use the equation - Kinematics eqution - V^2 = U^2 + 2as
As we wanna know the value of v / u this is the only equation which covers our information asked in question...
So when the sphere hits the plate V = 0 and u=u
so we can write that as 0 = u^2 + 2ah taking downwards direction as +ve direction ; that means u^2 = -2ah
And when the ball rebounds, u = 0 and v = v and height is halved.
so , v^2 = 0 + 2(-a)(h/2) = -ah as 2 and 2 gets canceled
so divide v^2 / u^2
= -ah / -2ah = 1 / 2
taking root on R.H.S will remove squares from L.H.S
so,
v/ u = 1 / root 2

Thankyu very much,yu r very helpful :***

 

[Adira Luis]

i got it

 

[Hanona]

Hanona
You are doing nice Job.

Thank you ! so are you as well

 

[Thought blocker]

Thank you ! so are you as well

Thanks Hanona

 

[Hanona]

Thanks

Anytime friend ^_^

 

[Thought blocker]

Anytime friend ^_^

 

[beeloooo]

can anyone explain me mcq number 20 ? how is it A ?

help will be extremely appreciated ?

 

[Thought blocker]

can anyone explain me mcq number 20 ? how is it A ?

help will be extremely appreciated ?

 

[Thought blocker]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s12_qp_11.pdf
Q36. Anyone?

When the switch is open, current goes through both resistors, since there is no other way for it to go. Tab dekhe to we can say that Voltmeter shows reading V (because there is current going through that resistor R2, so there will be potential difference across the resistor too) and there is some reading I on the ammeter, which is equal to (EMF of Source)/(R1 + R2).

(Just imagine the resistors have value R1 and R2).

But if we close the switch, hum dekh sakte hain ki current ko ek aur path nazar ata hai. So, it can go through first resistor, then miss out the second resistor, since current takes path of least resistance.

Therefore, second resistor will have Zero current going through it, so because V = IR, and I = 0, V becomes Zero. So the value of V decreases to Zero.

For I, we can write Current = (EMF of Source)/(R1) since R2 is no longer important in the circuit. Therefore, current increases since resistance of circuit decreases. So current I increases, and V decreases to Zero = B.

 

[Thought blocker]

Ah. I wish my mind worked that way. Thanks a lot!

Sagar helped me... and I modified it, simplu

 

[Thought blocker]

Idk who that is, but i appreciate the help. I wasted 20 minutes thinking of a logical reason for that question

I got the answer, but you know bored to type as time is money

 

[Thought blocker]

Haha right.

Doubts hain ?

 

[Thought blocker]

Nae, all clear.

 

[Catherine7532]

can u plz solve this question

Q. A mass of a liquid of density ρ is thoroughly mixed with an equal mass of another liquid of density
2ρ. No change of the total volume occurs.
What is the density of the liquid mixture?
A. 4/3 ρ B. 3/2ρ C. 5/3ρ D. 3ρ

BTW the answer is A.

 

[Thought blocker]

Liquid 1
mass = m
volume = v
density = p

liquid 2
mass = m
density = 2p
volume = 0.5v ( since the mass must be the same, to "balance" the 2p density, the volume must be half)

total density = m/v
which is:
2m/0.5v+v ,which works out to 4/3 (m/v)
so the answer is 4/3 (p)

can u plz solve this question

Q. A mass of a liquid of density ρ is thoroughly mixed with an equal mass of another liquid of density
2ρ. No change of the total volume occurs.
What is the density of the liquid mixture?
A. 4/3 ρ B. 3/2ρ C. 5/3ρ D. 3ρ

BTW the answer is A.

 

[Catherine7532]

Thanks a lot !!!

 

[Catherine7532]

can u plz solve q35. the answer is C.

 

[Hadi Murtaza]

can u plz solve q35. the answer is C.

Potential difference across R1 = 5 - 3 = 2 V
Potential difference across R2 = 3 - 2 = 1 V
Potential difference across R3 = 2 - 0 = 2 V

V = IR
R = V/I
R1 = 2/I
R2 = 1/I
R3 = 2/I

so ratio of R1 : R2 : R3 = 2 : 1 : 2 , same as da ratio of choice C