Piv txwv ntawm Cov Lus Nug Txog Lub Zog Hluav Taws Xob
1. Ib lub electron raug nrawm los ntawm qhov so los ntawm qhov sib txawv ntawm 12 volts. Qhov kev hloov pauv ntawm lub zog muaj peev xwm ntawm lub electron yog dab tsi?
Kev Sib Tham
Nws paub tias:
Thauj khoom 1 electron (e) = -1,60 x 10-19 Coulomb
Qhov sib txawv ntawm lub zog hluav taws xob = lub zog hluav taws xob (V) = 12 Volts
Nug: Kev hloov pauv ntawm lub zog hluav taws xob (ΔEP)
Lus teb:
ΔEP = q V = (-1,60 x 10-19 C)(12 V) = -19,2 x 10-19 Joule
Lub cim tsis zoo txhais tau tias lub zog hluav taws xob txo qis. Thaum nyob ze ntawm lub phaj uas muaj nqi tsis zoo, lub zog hluav taws xob ntawm lub electron yuav nyob rau ntawm nws qhov siab tshaj plaws. Tom qab mus txog ze ntawm lub phaj uas muaj nqi zoo, lub zog hluav taws xob ntawm lub electron yuav nyob rau ntawm nws qhov tsawg kawg nkaus.
2. Ob lub phaj sib luag muaj ob lub them hluav taws xob zoo thiab tsis zoo. Lub zog hluav taws xob ntawm ob lub phaj yog 500 Volts/meter. Qhov nrug ntawm ob lub phaj yog 2 cm. Txheeb xyuas qhov kev hloov pauv ntawm lub zog muaj peev xwm ntawm proton thaum nws txav ntawm lub phaj uas muaj hluav taws xob zoo mus rau lub phaj uas muaj hluav taws xob tsis zoo!
Kev Sib Tham
Nws paub tias:
Lub teb hluav taws xob nruab nrab ntawm ob lub phaj (E) = 500 Volts/meter
Qhov nrug ntawm ob lub phaj (s) = 2 cm = 0,02 meters
Lub zog proton = +1,60 x 10-19 Coulomb
Nug: Kev hloov pauv ntawm lub zog hluav taws xob (ΔEP)
Lus teb:
Ua ntej xam qhov sib txawv ntawm qhov muaj peev xwm lossis hluav taws xob voltage :
V = E s
V = (500 Volts/meter)(0,02 meters)
V = 10 Volts
Kev hloov pauv ntawm lub zog hluav taws xob:
ΔEP = q V
ΔEP = (1,60 x 10-19 C)(10 V)
ΔEP = 16 x 10-19 Joule
ΔEP = 1,6 x 10-18 Joule
Thaum nyob ze ntawm lub phaj uas muaj hluav taws xob zoo, lub zog hluav taws xob ntawm proton yuav nyob rau qhov siab tshaj plaws. Thaum mus txog ze ntawm lub phaj uas muaj hluav taws xob tsis zoo, lub zog hluav taws xob ntawm proton yuav nyob rau qhov tsawg kawg nkaus. Yog li ntawd, thaum txav ntawm lub phaj uas muaj hluav taws xob zoo mus rau lub phaj uas muaj hluav taws xob tsis zoo, lub zog hluav taws xob ntawm proton yuav txo qis.
3. Ob lub nqi tau teeb tsa raws li qhia hauv daim duab hauv qab no. Lub nqi ntawm A yog +9 μC thiab lub nqi ntawm B yog -4 μC. Coulomb's constant (k) = 9 x 109 Nm2C-2, 1 μC = 10-6 C. Lub zog fais fab ntawm tus nqi B hloov pauv ntau npaum li cas yog tias nws txav mus rau tus nqi A?
Kev Sib Tham
Nws paub tias:
Them A (q1) = +9 μC = +9 x 10-6 C
Tus nqi B (q1) = -4 μC = -4 x 10-6 C
Coulomb tus nqi tas mus li (k) = 9 x 109 Nm2C-2
Qhov nrug ntawm cov nqi A thiab B (r) = 10 cm = 0,1 meters = 10-1 'meter'
Nug: Kev hloov pauv ntawm lub zog hluav taws xob ntawm tus nqi B yog tias nws txav mus rau tus nqi A
Lus teb:
Tus nqi B txav mus rau tus nqi A kom nws lub zog hluav taws xob txo qis los ntawm 2,4 Joules.
Qhov no zoo ib yam li ib yam khoom loj txav mus rau hauv qab ntawm lub ntiaj teb kom nws qhov siab thiab lub zog gravitational txo qis.
4. Ib lub khoom me me uas muaj nqi ntawm \( q = 5 \times 10^{-6} \) C raug muab tso rau hauv ib lub teb hluav taws xob nrog lub peev xwm ntawm \( V = 300 \) V. Lub zog hluav taws xob ntawm lub khoom me me yog dab tsi?
Kev Sib Tham:
Lub zog fais fab yog muab los ntawm:
\[ U = q \times V \]
\[ U = 5 \times 10^{-6} \times 300 \]
\[ U = 1.5 \times 10^{-3} \] J
5. Muab ib lub electron tso rau hauv ib lub teb hluav taws xob uas muaj zog txog 500 V. Lub zog hluav taws xob ntawm lub electron yog dab tsi?
Kev Sib Tham:
Lub zog hluav taws xob (electron charge) q = -1.6 x 10^{-19} C.
\[ U = q \times V \]
\[ U = -1.6 \times 10^{-19} \times 500 \]
\[ U = -8 \times 10^{-17} \] J
6. Ib tug proton txav ntawm lub zog muaj zog ntawm 100 V mus rau 200 V. Qhov kev hloov pauv ntawm nws lub zog muaj zog yog dab tsi?
Kev Sib Tham:
Tus nqi proton \( q = 1.6 \times 10^{-19} \) C.
\[ \Delta U = q \times \Delta V \]
\[ \Delta U = 1.6 \times 10^{-19} \times (200 – 100) \]
\[ \Delta U = 1.6 \times 10^{-17} \] J
7. Ob yam khoom uas muaj cov nqi \( q_1 = 2 \times 10^{-6} \) C thiab \( q_2 = -3 \times 10^{-6} \) C raug muab tso rau hauv ib lub teb hluav taws xob uas muaj peev xwm ntawm \( V = 400 \) V. Lub zog tag nrho ntawm ob yam khoom yog dab tsi?
Kev Sib Tham:
\[ U_1 = q_1 \times V \]
\[ U_2 = q_2 \times V \]
\[ U_{total} = U_1 + U_2 \]
\[ U_{total} = (2 \times 10^{-6} + (-3 \times 10^{-6})) \times 400 \]
\[ U_{total} = -4 \times 10^{-3} \] J
8. Ib qho ion uas muaj nqi \(q = 4e \) (qhov twg \(e \) yog qhov them thawj zaug) nyob hauv ib lub teb hluav taws xob uas muaj peev xwm \(V = 250 \) V. Lub zog hluav taws xob ntawm cov ion yog dab tsi?
Kev Sib Tham:
\[ U = q \times V \]
\[ U = 4 \times 1.6 \times 10^{-19} \times 250 \]
\[ U = 1.6 \times 10^{-16} \] J
9. Paub tias ib lub khoom me me uas muaj lub zog ntawm q = -7 \times 10^{-5} \) C muaj lub zog peev xwm ntawm q = 2 \times 10^{-2} \) J. Lub zog peev xwm ntawm lub teb hluav taws xob qhov twg lub khoom me me nyob?
Kev Sib Tham:
\[ U = q \times V \]
\[ V = \frac{U}{q} \]
\[ V = \frac{2 \times 10^{-2}}{-7 \times 10^{-5}} \]
\[ V = -285.71 \] V
10. Ob yam khoom uas muaj cov nqi \( q_1 = 5e \) thiab \( q_2 = -2e \) nyob hauv ib lub teb hluav taws xob uas muaj peev xwm ntawm \( V = 300 \) V. Lub zog tag nrho ntawm ob yam khoom yog dab tsi?
Kev Sib Tham:
\[ U_1 = q_1 \times V \]
\[ U_2 = q_2 \times V \]
\[ U_{total} = U_1 + U_2 \]
\[ U_{total} = (5 \times 1.6 \times 10^{-19} – 2 \times 1.6 \times 10^{-19}) \times 300 \]
\[ U_{total} = 1.44 \times 10^{-16} \] J
11. Ib qho ion uas muaj nqi \( q = -3e \) muaj lub zog peev xwm ntawm \( -9.6 \times 10^{-19} \) J. Lub zog peev xwm ntawm lub teb hluav taws xob qhov twg qhov ion nyob yog dab tsi?
Kev Sib Tham:
\[ U = q \times V \]
\[ V = \frac{U}{q} \]
\[ V = \frac{-9.6 \times 10^{-19}}{-3 \times 1.6 \times 10^{-19}} \]
\[ V = 200 \] V
12. Paub tias lub zog fais fab ntawm tus nqi \( q \) hauv ib lub teb hluav taws xob nrog lub zog \( V = 450 \) V yog \( 9 \times 10^{-18} \) J. Tus nqi \( q \) yog dab tsi?
Kev Sib Tham:
\[ U = q \times V \]
\[ q = \frac{U}{V} \]
\[ q = \frac{9 \times 10^{-18}}{450} \]
\[ q = 2 \times 10^{-20} \] C
13. Ib qho nqi hluav taws xob zoo \( q = 1.5 \times 10^{-19} \) C raug tsiv ntawm ib qho chaw uas muaj peev xwm \( V_1 = 100 \) V mus rau \( V_2 = 500 \) V. Qhov kev hloov pauv ntawm lub zog muaj peev xwm yog dab tsi?
Kev Sib Tham:
\[ \Delta U = q \times \Delta V \]
\[ \Delta U = 1.5 \times 10^{-19} \times (500 – 100) \]
\[ \Delta U = 6 \times 10^{-17} \] J
