Lab Methods - Oscilloscope

The outputs of two electrical oscillators are compared on an oscilloscope screen. The oscilloscope spot is initially at the center of the screen. Oscillator Y is connected to the vertical terminals of the oscilloscope and oscillator X to the horizontal terminals. Which of the following patterns could appear on the oscilloscope screen, if the frequency of oscillator Y is twice that of oscillator X?

(GR9277 #17)

Solution:

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Answer:

Optics - Hologram

In an ordinary hologram, coherent monochromatic light produces a 3-dimensional picture because wave information is recorded for which of the following?

I. Amplitude
II. Phase
III. Wave-front angular frequency

A. I only
B. I and II only
C. I and III only
D. II and III only
E. I, II, and III

(GR8677 #58)

Solution:



Answer: B

Electromagnetism - Magnetic Field

A flat coil of wire is rotated at a frequency of 10 hertz in the magnetic field produced by three pairs of magnets as shown above. The axis of rotation of the coil lies in the plane of the coil and is perpendicular to the field lines. What is the frequency of the alternating voltage in the coil?

A. 10/6 Hz
B. 10/3 Hz
C. 10 Hz
D. 30 Hz
E. 60 Hz

(GR9277 #92)

Solution:

Answer:

Quantum Mechanics - Perturbation Theory

In perturbation theory, what is the first order correction to the energy of a hydrogen atom (Bohr radius a₀) in its ground state due to the presence of a static electric field E? 

A. 0
B. eEa₀
C. 3eEa₀
D. 8e²Ea₀³ / 3 
E. 8e²E²a₀³ / 3 

 (GR9277 #99) 

Solution



Answer: A