DO

Questions poorly answered

4.1

  1. How does a dielectric affect the capacitance of a vacuum-spaced capacitor? -answered well 1/3

  2. What is the equation for the energy stored in a capacitor?-answered well 1/3

  3. How does a capacitor charge and discharge through a resistor? -answered well 1/3

  4. what is the time constant (RC)? -answered well 1/3

4.2

  1. What are equipotential surfaces, and how do they relate to point charges?

  2. Under what conditions is the equation ΔUP = mgΔh applicable?-answered well 1/3

4.3

  1. What are Kepler's three laws of planetary motion? 1st 2nd -answered well 1/3

  2. How does Newton's law of gravitation (F = G M1M2 / r²) explain the motion of planets and satellites? Can you provide simple examples?

  3. How can Kepler's 3rd law be derived for the case of a circular orbit, using Newton's law of gravity and the formula for centripetal acceleration?-answered well 1/3

  4. How can data on orbital motion, such as period or orbital speed, be used to calculate the mass of a central object?-answered well 1/3

  5. What implications do the orbital speeds of objects in spiral galaxies have on the existence of dark matter? -answered well 1/3

  6. What is the relationship between the recently discovered Higgs boson and dark matter?

  7. How is the position of the centre of mass of two spherically symmetric objects determined, given their masses and separation, and how can their mutual orbital period in the case of circular orbits be calculated?

  8. How can a star's radial velocity be determined from data about the Doppler shift of spectral lines?

  9. How can the variation of radial velocities of bodies in a double system, such as a star and an orbiting exoplanet, be used to determine their masses for the case of a circular orbit edge-on as viewed from the Earth?

  10. How does the Hubble constant (H0) relate galactic radial velocity (v) to distance (D), and how is it defined by v = H0D?

  11. Why does 1 / H0 approximate the age of the universe?

  12. How can the equation ρc = 3H0² / 8𝛑G for the critical density of a 'flat' universe be derived simply using conservation of energy?

4.4

  1. What formula is used to calculate the magnetic field, B, when considering the force on a current-carrying conductor in a magnetic field?

  2. What is the relationship between the magnetic force on a moving charge and the magnetic field, and how is it expressed using F = Bq vsinΘ?

  3. What are the processes involved in producing a Hall voltage, and how does Hall voltage relate to magnetic field strength for a constant current?

  4. What are the shapes of the magnetic fields created by a current in a long straight wire compared to a long solenoid?

  5. How does adding an iron core affect the field strength in a solenoid?

  6. In what ways do current-carrying conductors exert forces on each other, and how can the directions of these forces be predicted?

  7. How are ion beams of charged particles quantitatively deflected in uniform electric and magnetic fields?

  8. What is the significance of the motion of charged particles in magnetic and electric fields within linear accelerators, cyclotrons, and synchrotrons?

4.5

  1. What is the definition of magnetic flux?

  2. What is flux linkage?

  3. What are Faraday's laws of electromagnetic induction?

  4. What is Lenz's law, and how does it relate to the direction of induced emf?

  5. How can you apply Faraday's and Lenz's laws to set up the equation for emf as the rate of change of flux linkage?

  6. Explain how an induced emf is generated in a linear conductor that moves at right angles to a uniform magnetic field.

  7. How does the position of a coil rotating in a magnetic field affect the instantaneous emf induced?

4.6