Q: Which of the following is the correct formula for the dot product of two vectors $$\vec{A}$$ and $$\vec{B}$$ with angle $$\theta$$ between them?

$$\vec{A} \cdot \vec{B} = AB \cos \theta$$

Q: Which of the following is the correct formula for the cross product of two vectors $$\vec{A}$$ and $$\vec{B}$$ with angle $$\theta$$ between them?

$$|\vec{A} \times \vec{B}| = AB \sin \theta$$

Question 1

A negatively charged particle is projected horizontally into a region between two parallel plates, with the top plate negatively charged and the bottom plate positively charged. What is the direction of the electric force acting on the particle?

Accepted Answer

Downward, toward the positively charged plate

Question 2

Given a uniform electric field $$\vec{E}$$ and a particle of charge $$q$$ and mass $$m$$, what is the acceleration $$\vec{a} of $$the particle?

Accepted Answer

$$\vec{a} = \frac{q\vec{E}}{m}$$

Question 3

An electron is projected horizontally into a uniform electric field between two plates. Which of the following best describes its trajectory?

Accepted Answer

It moves in a parabolic path

Question 4

Which kinematic equation would you use to find the final velocity $$v_f of a $$particle after time $$t if $$its initial velocity is $$v_i$$ and acceleration is $$a$$?

Accepted Answer

$$v_f = v_i + at$$

Question 5

A rod of length $$\ell$$ has a uniform linear charge density $$\lambda. $$What is the expression for the infinitesimal charge $$dq on a $$small segment $$dx$$?

Accepted Answer

$$dq = \lambda dx$$

Question 6

What is the general expression for the electric field $$\vec{E} at a $$point $$P$$ due to a continuous charge distribution?

Accepted Answer

$$\vec{E} = k \int \frac{dq}{r^2$} \hat{r}$$

Question 7

For a rod of length $$\ell$$ and total charge $$Q$$, what is the linear charge density $$\lambda$$?

Accepted Answer

$$\lambda = \frac{Q}{\ell}$$

Question 8

What is the electric field at a point $$P a $$distance $$a$$ from one end of a uniformly charged rod of length $$\ell$$ and total charge $$Q ($$along the axis of the rod)?

Accepted Answer

$$E = \frac{kQ}{a(\ell + a)}$$

Question 9

Which of the following best defines electric flux $$\Phi_E$$ through a surface of area $$A in a $$uniform electric field $$E$$ perpendicular to the surface?

Accepted Answer

$$\Phi_E = EA$$

Question 10

If the electric field $$E$$ makes an angle $$	heta$$ with the normal to a surface of area $$A$$, what is the electric flux through the surface?

Accepted Answer

$$\Phi_E = EA \cos 	heta$$

Question 11

Which of the following statements about electric flux through a closed surface is correct?

Accepted Answer

The net flux is proportional to the net number of field lines leaving minus entering the surface.

Question 12

Which of the following is the correct formula for the dot product of two vectors $$\vec{A}$$ and $$\vec{B}$$ with angle $$	heta$$ between them?

Accepted Answer

$$\vec{A} \cdot \vec{B} = AB \cos 	heta$$

Question 13

Which of the following is the correct formula for the cross product of two vectors $$\vec{A}$$ and $$\vec{B}$$ with angle $$	heta$$ between them?

Accepted Answer

$$|\vec{A} 	imes \vec{B}| = AB \sin 	heta$$

Question 14

Which of the following best describes the physical meaning of electric flux?

Accepted Answer

It is proportional to the number of electric field lines passing through a surface.

Question 15

A surface of area $$A is $$placed in a uniform electric field $$E. If $$the surface is parallel to the field, what is the electric flux through the surface?

Accepted Answer

$$\Phi_E = 0$$

Question 16

Which of the following is the correct expression for the amount of charge $$dq in a $$small volume element $$dV$$ with volume charge density $$\rho$$?

Accepted Answer

$$dq = \rho dV$$

Question 17

A cube is placed in a uniform electric field such that the field lines pass perpendicularly through two faces and are parallel to the other four faces. What is the net electric flux through the cube?

Accepted Answer

Zero

Question 18

Which of the following is the correct unit for electric flux?

Accepted Answer

$$\mathrm{N \cdot m^2$ / C}$$

Continuous Charge Distributions and Electric Flux: Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard