Physics MCQs thread.

[Xthegreat]

mass= 2x 10^-3( print not clear)

the PRINT NOT CLEAR explains ALOT!! wth..lol

 

[aliya_zad]

Yeah otherwise u get it 4 kj!!

 

[melon159]

what's the ans for 10 hassam??? c??

 

[Xthegreat]

how its .07 j

it wants the ADDITIONAL strain energy.
so at 6N, the extension is 0.03m, E = 0.09
then when it is extended another 0.01m, it becomes 0.04m which is 8.0N
the E = 0.16

0.16-0.09 = 0.07J

 

[melon159]

QQ..The electric field at a certain distance from an isolated alpha particle is 3.0 x 10^7 NC-1
What is the force on an electron when at that distance from the alpha particle??
a. 4.8 x 10^-12
b. 9.6 x 10^-12
c. 3.0 x 10^7
d. 6.0 x 10^7

 

[Xthegreat]

QQ..The electric field at a certain distance from an isolated alpha particle is 3.0 x 10^7 NC-1
What is the force on an electron when at that distance from the alpha particle??
a. 4.8 x 10^-12
b. 9.6 x 10^-12
c. 3.0 x 10^7
d. 6.0 x 10^7

F= Eq
F = 3 x 10^7 x 1.6 x 10 ^(-19)
F = A

the q is always the charge of the charge that is moving, not the charge of the electric field

 

[kakarocks]

work will be integral of this F against extensiongraph equation

I think A , What's the real answer?

 

[kakarocks]

A?

 

[examfearz]

can nyone explain the working of this question??

 

[melon159]

young modulus=(f x L)/(A x e)
2.0 x 10 ^ 11=(20/ pie d^2/4) x (L/e)
then calculate (e/l) x 100 % which is 5.1 x 10^-2

 

[rabib2013]

can anyone tell me the answer of question number 2 of may june 2001.. apparently, the mark scheme isn't available on any site :\

 

[melon159]

whats the question??

 

[rabib2013]

its this question abt forces acting on different positions of a circular disc.. they asked to find the direction of the resultant force.. sorry i cant give any direct link cause i cant find its soft copy on the net :\

 

[Saturation]

How is it 0! , can someones pls show me the directions in which the 3 forces must act in order to produce a resultant of 0!?

 

[examfearz]

how do we solve this??

 

[Xthegreat]

how do we solve this??

m1v1 = m2v2
2 x 2 = 1 x v
v = 4ms-1

E = 1/2 x m x v2 + 1/2 x m x v2
E = 1/2 x 2 x 2^2 + 1/2 x 1 x 4^2
E = 12J

 

[RafaySid]

How is it 0! , can someones pls show me the directions in which the 3 forces must act in order to produce a resultant of 0!?

Take the resultant vector of 3 and 4 by the pythagoras theorem. The 3 and 4 N forces will be perpedicular to each other while the 5 N force will act at the vertex of it.

 

[MHHaider707]

Hey can anyone please tell me that what is terminal voltage???

 

[libra94]

its the voltage around any component in the circuit (the component can be bulb/thermister/resister...etc)

 

[MHHaider707]

Is it not the voltage acros a battery when it has an internal resistance??