Oscillations/Waves
In taking your pulse, you count 78 heartbeats in 1 min. What is the frequency of the oscillation?
1.3 Hz
Light of wavelength 1 illuminates a double slit and an interference pattern is observed on a screen. When the wavelength is changed, the fringes get closer together. Is the second wavelength larger or smaller than the first?
Smaller
What is the potential difference across each resistor when 3 resistors are each wired in parallel with a 10 V battery?
10 V
When you are in the southern hemisphere, does a compass point north or south?
North (independent of hemisphere)
How do you know when to use the ray model vs the wave model of light?
The wave model should be used when dealing with small slits comparable to the wavelength of light
What is the difference between a transverse and a longitudinal wave?
The displacement of a transverse wave is perpendicular to the direction the wave travels. The displacement of a longitudinal wave is parallel to direction wave travels.
What is the magnetic field amplitude of an electromagnetic wave whose electric field amplitude is 10 V/m?
3.3*10^(-8) T
Which of Newton's laws explains that the electric force of charged particle A on charged particle B is equal in magnitude and opposite in direction to the electric force of B on A?
Newton's 3rd law
An electron is at rest in a magnetic field of strength 10^(-4) T. What is the magnitude of the force on the electron?
0 N
In snell's law (n1sin(theta1)=n2sin(theta2)), the angles theta are measured with respect to which line?
The normal
Consider the function x(t)=A*cos(2*pi*t/T). What are the units of (2*pi*t/T)?
Radians
What is the energy (in eV) of a photon of visible light that has a wavelength of 500 nm?
E=hf=hc/(lambda)=2.5 eV
What is the strength and direction of the electric field 1.0*10^(-3) m from an electron?
1.4 10^(-3) N/C, toward the electron
A proton moves at a speed v>0 out of the page. The magnetic field points straight up on the page. What is the direction of the magnetic force?
To the left
A lens has a focal length of 0.5 m. What is the power of the lens?
2.0 Diopter
Consider the function x(t)=1*cos(2*pi*t/T). What is the value of x at t=0?
1
How many anti-nodes are there for an m=3 standing wave on a string?
3
An electron moving at a speed of 5*10^(6) m/s is brought to rest by an electric field. Did the electron move to a region of higher or lower potential?
Because the electron is a negative charge and it slows down as it travels, it must be moving from a region of higher potential to a region of lower potential.
The current in a loop of wire flows counter-clockwise on the page. What is the direction of the magnetic field produced by the wire?
Out of the page
How far does a rock appear to be under the water when it is actually 0.5 m under water? The index of refraction for water is n=1.33.
0.38 m
A plane wave, a circular wave, and a spherical wave all have the same intensity. Each wave travels the same distance. Afterward, which wave has the highest intensity?
A plane wave does not spread out, so it's intensity will remain constant. The other two waves spread out, so their intensity will decrease.
An electron and a proton are both accelerated from rest through a potential difference of 100 V. Afterwards, which particle has a larger de Broglie wavelength?
The electron
At one point in space the electric potential energy of a 15*10^(-9) C charge is 45*10^(-6) J. What is the electric potential at this point?
3000 V
The magnetic field 10 cm from a wire carrying a current of 1 A is 2*10^(-6) T. What is the magnitude of the field 1 cm from the wire?
20*10^(-6) T
A 2.0 cm object is 40 cm from a converging lens with a 20 cm focal length. What is the image position?
40 cm