Incorrect Past Papers Flashcards
Explain how stationary waves are produced
The incident and reflected waves interfere
How can measuring 14 half wavelengths be better than measuring just 2 adjacent fringe separations
Measuring multiple fringe separations Reduces uncertainty in d
Explain quantum tunnelling
A quantum particle can exist in a position where in classical physics, its has insufficient energy to occupy
Units for momentum
Kgms^-1
State whether the energy required to move point P via path A will be more or less or equal to the nergry required to mngr to P by path B
P. <——
^. Oo. |
A| O. O |B
|. Oo. |
Probe ——
Equal since the energy required to move two points in a gravitational field is independent of path taken
As probe from earth travels further away the clock’s desynchronisation. Will they run faster or slower
Faster
The will have a weaker gravitational field
State what is meant by a gravitational potential of -1.7*10^9 Jkg^-1
1.7*10^9 joules of energy transferred in moving unit mass from infinity to that point
Explain why the diameter of the sun will increase as it become a red giant
The thermal pressure inside the sun with exceed the gravitational forces
why can larger particles like muons can be regarded as particle
The de broglie wavelength is to small for interference or diffraction to be seen
Explain why alpha particles travel through magnetic field of earth follow a helical path
They have a velocity perpendicular to the field that has a circular motion
They have a velocity parallel to the field that has a linear motion
High altitude large cosmic ray observatory which is close to the South Pole. Why is this location good
High up so it’s closer to cosmic rays and reduces interaction with atmosphere
At a location where earth has a stronger magnetic field
Why does a dc ammeter will display a greater current than a AC current
AC current will generate reactance in the inductor
What’s the units for phase difference
Rad
A student looks at a lamp through a filter, the student rotates the filter 90°. What effect does it have on the observed brightness
No effect since a lamp light is unpolarised
Student uses glasses to watch a 3D movie, they contain two polarising filters, one for each eye. EXPLAIN HOW THIS ARRANGEMENT ENABLES A DIFFERENT IMAGE TO BE SEEN BY EACH EYE
Only one projected image to pass through to each eye
There are two projectors, showing two different images each one with a polarizing filter. A student looks through one filter of his glasses and rotates it 90°. Explain why he does not observe any change in brightness
The image from one projector will decrease while the other project increases in brightness
When finding the luminosity of a star, what assumptions do you make of it
It’s a black body
What happens to the radius of the sun when it will turn into a red giant
Radius increases due to thermal pressure is greater than gravitational forces
The radius then stops increasing as thermal pressure and yea force balance
Considering a magnetic field around the In the inductor, explain why the back emf produced is large enough to allow a lamp to flash
Rapid change in current
Explain how back emf is produced
Changing current produces a change in magnetic field which induces a back emf in the conductor
Why should a value for a constant be taken from a graph
Range of values
What type of light does rainbow have
Plane polarised
Why does the brightness decrease from the ends of a rainbow to the highest point
A rainbow has plane polarised light
There’s a gradual decrease as the rainbow goes from vertical to horizontal
What’s the phase change in radians from a low dense medium to high dense medium
Pi
