Physics: Post your doubts here!

[megamind]

i need physic telecomunication help​

what is the function of
DAC​

serial to parallel converter​

and af amplifier​

​

 

[megamind]

can any one help me please i am at the point of death​

 

[gary221]

i need physic telecomunication help​

what is the function of​

DAC​

serial to parallel converter​

and af amplifier​

​

DAC = produces an analogue signal from the sampled binary digits.
serial to parallel = the same.
a.f. amplifier = amplifies the analogue signal n passes it to the ADC.

 

[Haider2011]

https://www.xtremepapers.com/commun...mistry-with-marking-scheme.24463/#post-485123

 

[cyclone94]

salamz
sm1 plz help wid dis
state wat is meant by a tesla..........it comes for 3 mks............
i only noe 1 point ie. it is d SI unit of magnetic flux density.......wt more points r der for dis...???

 

[xxfarhaxx]

salamz
sm1 plz help wid dis
state wat is meant by a tesla..........it comes for 3 mks............
i only noe 1 point ie. it is d SI unit of magnetic flux density.......wt more points r der for dis...???

1 tesla is the uniform magnetic flux density, which actiing normally to a long straight wire of length 1m carrying a current of 1A, acting perpendicular to the magnetic field, producing a force of 1N on the conductor...

u jst hav to define the equation B=F/Il

 

[cyclone94]

1 tesla is the uniform magnetic flux density, which actiing normally to a long straight wire of length 1m carrying a current of 1A, acting perpendicular to the magnetic field, producing a force of 1N on the conductor...

u jst hav to define the equation B=F/Il

Jazakallah

 

[1357913579]

DAC = produces an analogue signal from the sampled binary digits.
serial to parallel = the same.
a.f. amplifier = amplifies the analogue signal n passes it to the ADC.

Assalamoalikum wr wb

Can anyone please tell me the advantages of Radio waves over other methods of communication?
Jazak Allah khairn.

 

[Tkp]

oct nov 11 qp 23-2cii

 

[gary221]

Assalamoalikum wr wb

Can anyone please tell me the advantages of Radio waves over other methods of communication?
Jazak Allah khairn.

Radio waves(high frequency):
i) have high bandwidth n can carry a large amnt of info.
ii) can be transmitted as narrow beams which r more secure.
iii) r line-of-sight n often use a satellite.

 

[Adorkableme]

Can someone please help me with question 13.........

http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_w10_qp_11.pdf

 

[gary221]

Can someone please help me with question 13.........

http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_w10_qp_11.pdf

Moment of force = force * perpendicular distance from pivot
1) So, force = 10 N, dist from pivot = 2 m. So, moment = 10 * 2 = 20 Nm in 1 direction.
2) Force = 5 N, dist from pivot = (4-2) = 2m. So, moment = 5*2 = 10 Nm in same direction.
So, total moment = 10 + 20 = 30 Nm.

3) force = 15 N, dist from pivot = 3 m. So, moment = 15 * 3 = 45 Nm in the opp direction.

Thus, total moment = 45 - 30 = 15 Nm
So, ans = A

 

[goodluckayesha]

I got to know the apparatus for practicals 31 but no idea wht cud the experiment be

 

[mutilated_grass]

http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_w12_qp_12.pdf

Hey guys

It's question 10 from oct/nov 2012 paper 12

Regarding the projectile motion graph, why can't it be a straight line as shown by B? Assuming there is no air resistance, the horizontal velocity has no acceleration and the vertical component has constant acceleration; therefore the graph should have straight lines instead of a curve....the answer is D and I'm not sure why.

 

[daredevil]

May 2011 p11 Q9 Q10 Q13
May 2011 p12 q17 2 34 37 15 10 19 32
Please solve these questions for me and explain too

 

[haha101]

wha

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w12_qp_12.pdf

Hey guys

It's question 10 from oct/nov 2012 paper 12

Regarding the projectile motion graph, why can't it be a straight line as shown by B? Assuming there is no air resistance, the horizontal velocity has no acceleration and the vertical component has constant acceleration; therefore the graph should have straight lines instead of a curve....the answer is D and I'm not sure why.

whats the answer ?

 

[hassankhan]

th

First of all data you are provided with
Frequency = 125 hz
tension = 4n
wavelength = 17.8/100 = 0.178m (Note : this length is given for anti node seperation, and wave length is between 2 alternative anti nodes or nodes)
therefore : 0.178 * 2 = 0.356 m (this length is of wavelength )

V= f*wavelength
v = 125 * 0.356
v = 44.5 m/s

now rooting on both sides
m = 4/44.5^2
m = 2.1 x 10^-3

thnks a lot man...

 

[gary221]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w12_qp_12.pdf

Hey guys

It's question 10 from oct/nov 2012 paper 12

Regarding the projectile motion graph, why can't it be a straight line as shown by B? Assuming there is no air resistance, the horizontal velocity has no acceleration and the vertical component has constant acceleration; therefore the graph should have straight lines instead of a curve....the answer is D and I'm not sure why.

It cant be B, as the velocity of the skier will never be constant (due to gravitational acceleration).
So, only curved lines, not straight!!

 

[gary221]

May 2011 p11 Q9 Q10 Q13
May 2011 p12 q17 2 34 37 15 10 19 32
Please solve these questions for me and explain too

s11 p12

2) You just have to remember the formula (n hence the units) of the given quantities. ie energy = force * displacement (N * m). so, a is correct.
b) power = work/ displacement (J/s) which is clearly wrong. Hence ans = b)

10) Force= mass * acceleration. Clearly the direction of the force is decided by the dir. of acceleration (which is the only vector quantity).
So, force n acceleration MUST be in the same direction.
Whereas acceleration = velocity/ displacement (both vector quantities). So, dir of acceleration may nt b d same as velocity.

 

[gary221]

15) For 2 forces to be a couple, they must b in the opp dir, perpendicular to the object----> http://www.s-cool.co.uk/a-level/physics/moments-couples-and-equilibrium/revise-it/couples
So, only B fulfils tht category. A will cause a resultant force. C= no resultant force n no couple. D = forces nt parallel, hence nt a couple.

19) Energy = Force * displacement
10 = x * 5 *10^(-3) m
So, x= 10 /(5 *10 ^-3) = 2000 N
ans = D