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Question 1:


Five particles charged with the same charge +q move with the same speed v in a magnetic field B, as shown above. Which particle experiences the highest magnetic force?

Question 2:
Two wires of circular cross-sectional areas have resistances R₁ and R₂.
If ρ₁ = 2ρ₂, l₁ = 2l₂ and r₁ = 2r₂, what is the ratio R₁/R₂?
ρ₁, ρ₂ are the resistivities of the two wires,
l₁, l₂ are the lengths of the two wires,
r₁, r₂ are the radii of the two wires.

Question 3:


Two wires carry identical currents I, as shown above. At which point is the magnetic field the strongest?

Question 4:



Two metallic bars slide along metallic rails at speeds v₁ = .1m/s and v₂ = .2m/s as shown above. The bar and the rails are situated in a magnetic field of 4T. What is the induced voltage in the bar and rails?

Question 5:
A police car with its siren on travels at a speed v₁ toward a person. The frequency of the siren is f₁ and the person hears the sound at a frequency f₂. If v_s is the speed of sound, v₁ =

Question 6:
Violet light has a wavelength of 400nm. What is its frequency, if the speed of light is 3·10⁸?

Question 7:
The activity of a radioactive sample at time t = 0s is A₀ and the activity of the same radioactive sample at time t₁ is A₁. What is the decay constant of the sample?