סטאַטישע עלעקטריע – פּראָבלעמען און לייזונגען

סטאַטישע עלעקטריע – פּראָבלעמען און לייזונגען

עלעקטרישע קראַפט

1. פונקט א אין אן עלעקטרישן פעלד . די גרייס פון דעם עלעקטרישן פעלד ביי פונקט א = 0.5 NC -1 . אויב א 0.25-C לאדונג ווערט געשטעלט ביי פונקט א, וואס איז דעמאלט די עלעקטרישע קראפט וואס ווערט אויסגעאיבט אויף דער לאדונג?

באַקאַנט:

עלעקטריש פעלד ביי פונקט A = 0.5 NC -1

עלעקטרישע לאדונג ביי פונקט A = 0.25 C

געוואָלט: עלעקטרישע קראַפט

לייזונג:

פֿ ​​= ק ע

F = (0.25 C)(0.5 NC -1 )

F = 0.125N

2. Two charges 5 C and 4 C are separated by a distance of 3 meters. If Coulomb constant is 9 × 109 Nm2 C-קסנומקס, what is the magnitude of electric force experienced by two charges?

באַקאַנט:

אָפּצאָל 1 (ק1) = 5 C

אָפּצאָל 2 (ק2) = 4 C

Distance between charge 1 and charge 2 (r) = 3 meters

Coulomb’s constant (k) = 9 × 109 Nm2 C-קסנומקס

געוואָלט: The magnitude of the electric force (F)

לייזונג:

Static electricity – problems and solutions 1

3. Electric charge +q1 = 10 μC ; +q2 = 20 μC ; and q3 are separated, as shown in figure below. The electric force exerted on charge q2 = 0, then what is the charge of q3.

Static electricity – problems and solutions 2

באַקאַנט:

לאַדונג 1 (q² ) = 10 μC = 10 x 10⁻⁶ C

לאַדונג 2 (q² ) = 20 μC = 20 x 10⁻⁶ C

געוואָלט: What is the charge of q3

לייזונג:

There are two forces acts on +q2.

The first force is the repulsive force between charge +q1 and charge +q2 that is F12, rightward.

The net electric force acts on q2 = 0 then q3 must negative.

The second force is the attractive force between charge +q2 and -q3 that is F23, leftward.

Both of these forces act on q2, have the same magnitude but the opposite direction.

Static electricity – problems and solutions 3

Net force acts on +q2 = קסנומקס.

Static electricity – problems and solutions 4

4. Three charges q1, q, and q2 are in a line. If q = 5.0 μC and d = 30 cm, then what is the magnitude and direction of the electric force acts on the charge q.

Static electricity – problems and solutions 5

באַקאַנט:

אָפּצאָל 1 (ק1) = 30 μC = 30 x 10-6 C

אָפּצאָל 2 (ק2) = 60 μC = 60 x 10-6 C

Charge 3 (q) = 5 μC = 5 x 10-6 C

דיסטאַנץ צווישן q1 and q = d

דיסטאַנץ צווישן q2 and q = 2d

d = 30 cm = 0.3 meters

ד² = (0.3) ² = 0.09

Coulomb’s constant (k) = 9 x 109 ן עם2 C-2

געוואָלט: The magnitude and the direction of the electric force acts on the electric charge

לייזונג:

There are two forces act on q that is F1 rightward (q and q1 are positive so F1 away from q and q1) and F2 leftward (q and q2 are positive so F2 away from q and q2). First calculated F1 און פ2.

Static electricity – problems and solutions 6The net force is 7.5 Newton. The direction of the net force = the direction of F1, rightward point to charge q2.

זע אויך  ניוטאָנס געזעצן פון באַוועגונג – פּראָבלעמען און לייזונגען

עלעקטריש פעלד

5. א פונט אָפּצאָל q is at the point P in the electric field געשאפן by the charge (+) so that it experiences a force of 0.05 N in the direction towards the charge. If the magnitude of the electric פעלד at point P is 2 x 10-2 NC-1, דעמאָלט וואָס איז the magnitude and type of charge that causes the עלעקטריש פעלד.

באַקאַנט:

Electric force (F) = 0.05 N

Electric field (E) = 2 x 10 -קסנומקס NC -קסנומקס = 0.02 NC -קסנומקס

געוואלט: The magnitude and type of electric charge

לייזונג:

The electric charge is calculated using a formula that expresses the relationship between electric force (F), the electric field (E) and electric charge (q):

פֿ ​​= ק ע

q = F / E = 0.05 N / 0.02 NC –1 = 2.5 קולאָמבס

The charge q experiences an electric force in the direction to charge (+) which produces an electric field, so the charge q is negative.

6. Charge A and B are separated by a distance of 4 meters. Point C is between both charges, 1 meter from point A. If QA = –300 μC, QB = 600 μC. 1/4 π ε0 = 9 × 109 ן עם2 C– 2, then what is the magnitude of the electric field at point C produced by both charges.

באַקאַנט:

דיסטאַנץ צווישן לאָדונגען A און B (rAB) = 4 מעטער

Distance between point C and charge A (rAC) = 1 מעטער

Distance between point C and charge B (rBC) = 3 מעטער

לאָדונג א (qA) = –300 μC = -300 x 10-6 C = -3 x 10-4 קאָלאָמב

לאָד ב (qB) = 600 μC = 600 x 10-6 C = 6 X 10-4 קאָלאָמב

Constant (k) = 9 × 109 ן עם2 C-קסנומקס

געוואָלט: Electric field at point C

לייזונג:

Electric field produced by charge A at point C :

Static electricity – problems and solutions 7

אָפּצאָל A is negative so that the direction of the electric field point to charge A and away from charge B (to left).

The electric field produced by charge B on point C :

Static electricity – problems and solutions 8

Charge B is positive so that the direction of electric field away from charge B and point to charge A (to left).

דער רעזולטאַט פֿון דעם עלעקטרישן פֿעלד בײַ פּונקט A:

E = E A + E B

E = (27 x 10⁻⁶ ) + (6 x 10⁻⁶ )

E = 33 x 10 5 N/C

The direction of the electric field point to charge A and away from charge B (to left).

7. A 1-mg dust float in the air. If the charge of the dust is 0.5 μC and acceleration due to gravity is 10 m/s2, determine the magnitude of the electric field that supports dust.

באַקאַנט:

Mass of dust (m) = 1 mg = 1 x 10-6 kg

Charge of dust (q) = 0.5 μC = 0.5 x 10-6 C

זע אויך  גיכקייט פון טראַנסווערסאַלע כוואַליעס – פּראָבלעמען און לייזונגען

אַקסעלעראַציע צוליב גראַוויטאַציע (g) = 10 m/

געוואָלט: עלעקטריש פעלד

לייזונג:

וו = מג

w = weight of dust, m = mass of dust, g = acceleration due to gravity

The force of gravity acts on dust :

וו = מג = (1 x 10-6 ק"ג )(10 מעטער/סעקונדע 2 ) = 10 x 10-6 ק"ג מעטער/סעקונדע 2 = 10 x 10-6 ניוטאנס

The equation of the electric field :

E = F/q

E = electric field, F = electric force, q = electric charge

Substitute F in the equation of electric field with w in the equation of weight :

E = F/q = w/q

E = (10 x 10 -6 N) / (0.5 x 10 -6 C)

E = 10 N / 0,5 C

E = 20 N/C

8. צוויי טשאַרדזשיז q1 = 32 μC און q2 = -214 μC are separated by a distance of x, as shown in figure below. No electric field at point P located at 10 cm from q2. Find x.

Static electricity – problems and solutions 9

באַקאַנט:

Charge 1 (Q1) = 32 מיקראָצעל

Charge 2 (Q2) = -214 מיקראָצעלוס

Distance of point P from q1 = x + 10 ס״מ

The distance of point P from q2 = 10 סענטימעטער

געוואלט: x

לייזונג:

Static electricity – problems and solutions 10

E1 = electric field produced by charge Q1. The direction of the electric field away from Q1 because Q1 is positive. E2 = electric field produced by Q2. The direction of the electric field point to Q2 because Q2 איז נעגאַטיוו.

No net force at point p located at 10 cm from Q2

Static electricity – problems and solutions 11

ניצט די קוואַדראַטישע פאָרמולע:

Static electricity – problems and solutions 12

9. A charged point q is at the point P in the electric field געשאפן by the charge (+), thus having a force of 0.05 N. If the charge is +5 × l0-קסנומקס Coulomb, then what is the magnitude of the electric field at point C.

באַקאַנט:

Electric force (F) = 0.05 Newton

Electric charge (Q) = +5 × l0-קסנומקס קולאָמב = 0.000005

געוואָלט: Electric field at point P

לייזונג:

ע = פֿ / ק

E = 0.05 ניוטאן / 0.000005 קולאָמב

E = 5 ניוטאן / 0.0005 קולאָמב

E = 10,000 ניוטאן/קולאם

E = 10 4 N/C

E = 10 4 NC -1

  1. וואָס איז סטאַטיק עלעקטרע? ענטפער: Static electricity refers to the buildup of electric charge on the surface of objects. It’s called “static” because the charges remain in one area rather than moving or flowing as in current electricity.
  2. How is static electricity generated? ענטפער: Static electricity is often generated through the process of triboelectric charging, where certain materials become charged when they come into frictional contact with a different material. Rubbing a balloon against hair or walking across a carpet in rubber-soled shoes can lead to the buildup of static charges.
  3. Why do you sometimes get a shock when touching a doorknob after walking on a carpet? ענטפער: Walking on a carpet, especially in dry conditions, can cause a buildup of static charges on your body. When you touch a doorknob or another conductor, the charges can discharge quickly, resulting in a static shock.
  4. How does humidity affect static electricity? ענטפער: Humidity tends to reduce the buildup of static electricity. The water molecules in the air can help dissipate electric charges. On drier days, there’s a higher likelihood of experiencing static buildup and shocks.
  5. Why are some materials more prone to developing a static charge than others? ענטפער: Materials differ in their ability to hold or transfer electrons. Some materials, like rubber or certain plastics, tend to gain or lose electrons more easily than others, making them more prone to static charge buildup.
  6. What is the principle behind an electroscope? ענטפער: An electroscope is a device used to detect the presence of a static charge. It typically consists of a metal rod connected to two thin leaves of metal foil. When a charged object is brought near the rod, the leaves move apart due to the repulsion of like charges, indicating the presence of static electricity.
  7. How does grounding eliminate static charges? ענטפער: Grounding provides a path for excess charge to move to the Earth, which is a vast reservoir of charges. When a statically charged object is grounded, the extra charges are neutralized, reducing or eliminating the static buildup.
  8. Why might you see sparks in a grain silo or during the refueling of an airplane, and why is this dangerous? ענטפער: Grain moving or rubbing against surfaces can generate static electricity, and the same goes for the flow of fuel. If there’s a buildup of static charge, it can discharge as a spark. In environments with flammable gases, dust, or liquids (like in a grain silo or during airplane refueling), these sparks can ignite the flammable material, leading to explosions.
  9. How do antistatic sprays or products work? ענטפער: Antistatic sprays and products typically contain substances that make surfaces slightly conductive. By doing so, they prevent the buildup of static charges or help dissipate any charges that do build up.
  10. What is the triboelectric series? ענטפער: The triboelectric series is a list that ranks materials based on their tendency to become positively or negatively charged when rubbed against another material. Materials at the top of the list tend to become positively charged, while those at the bottom tend to become negatively charged.