Lorentz force Quiz 1

Question 1

An electron in the presence of electric field $$0.24	ext{ V}{{	ext{m}}^{-1}}$$ and magnetic field $$0.12	ext{ T}$$ is being deviated inside a tube to hit a particular target. Suppose that this electron is moving perpendicular to the magnetic field with a velocity of $$4	imes {{10}^{4}}	ext{ m}{{	ext{s}}^{-1}}$$. Then, the magnitude of force required for deviation is

Accepted Answer

$$7.68	imes {{10}^{-16}}$$

Answer

$$9.63	imes {{10}^{-15}}$$

Answer

$$5.99	imes {{10}^{-14}}$$

Answer

$$2.46	imes {{10}^{-18}}$$

Question 2

Suppose that Lorentz force on a particle is equally distributed with its contributing counterparts. If the particle is moving parallel to the magnetic field, which of the following statements is correct?

Accepted Answer

Electric field acting on the particle is zero

Answer

Electric field and magnetic field acting on the particle are perpendicular to each other

Answer

Electric field acting on the particle is parallel to velocity of particle

Answer

Nothing can be predicted

Question 3

The difference between Lorentz force and electric force on a particle is equal to the product of charge on the particle and velocity of the particle. The angular deviation between the magnetic field and velocity of the particle is

Accepted Answer

$${{\sin }^{-1}}\left( \dfrac{1}{B} \right)$$

Answer

$${{\sin }^{-1}}\left( \dfrac{1}{v} \right)$$

Answer

$${{	an }^{-1}}\left( \dfrac{1}{B} ight)$$

Answer

$${{	an }^{-1}}\left( \dfrac{1}{v} ight)$$

Question 4

The magnetic force acting on a positron is equal to $$0.02	ext{ T}$$. What would be the magnitude of Lorentz force on the positron if an electric potential of $$3	ext{ V}$$ acts on it at a distance of $$0.02	ext{ cm}$$?

Accepted Answer

$$5.5	imes {{10}^{-2}}$$

Answer

$$6.5	imes {{10}^{-3}}	ext{ }$$

Answer

$$3.6	imes {{10}^{-4}}	ext{ }$$

Answer

$$7.2	imes {{10}^{-1}}	ext{ }$$

Question 5

Mark the wrong statement/statements: If the ratio of Lorentz force and electric force on a particle of mass $$2	imes {{10}^{-16}}	ext{ kg}$$ is equal to $$2$$, $$ \ $$ $$(A)$$ magnitude of Lorentz force is equal to magnitude of magnetic force on the particle $$ \ $$ $$(B)$$ magnitude of electric force is equal to magnitude of magnetic force on the particle

Accepted Answer

only B

Answer

only A

Answer

Both A and B

Answer

Neither A nor B