3 ngā pātai mō ngā whārite mara hiko
1. He pōro kawe hiko, he 10 cm te whānui, he 500 μC te utu hiko. Kei te rārangi o te pokapū o te pōro ngā pūwāhi A, B, me C i te tawhiti o te 12 cm, 10 cm me te 8 cm mai i te pokapū o te pōro. Tātaihia te kaha o te mara hiko i ngā pūwāhi A, B, me C!
Kua mohiotia:
Ko te radius o te pōro kawe (R) = 10 cm = 0.1 m
Utu hiko (q) = 500 μC = 500 x 10 -6 C
r A = 12 cm = 0,12 m
rB = 10 cm = 0,1 m
r C = 8 henimita = 0,08 mita
Pūmau Coulomb (k) = 9 x 10 9
E hiahiatia ana: Te kaha o te papa hiko i te pūwāhi A (E A ), i te pūwāhi B (E B ) me te pūwāhi C (E C )
Rongoā:
a) Te kaha o te papa hiko i te pūwāhi A
EA = kq / r A2 = (9 x 109 ) (500 x 10 -6 ) / (0,12) 2 = (4500 x 103 ) / 0,0144 = 312500 x 103 = 3,125 x 108 N/C
b) Te kaha o te papa hiko i te pūwāhi B
E B = kq / r B 2 = (9 x 10 9 )(500 x 10 -6 ) / (0,1) 2 = (4500 x 10 3 ) / 0,01 = 450.000 x 10 3 = 4,5 x 10 8 N/C
c) Te kaha o te papa hiko i te pūwāhi C
E C = 0 mō te noho i roto i te pōro.
2. Mēnā ka whakatakotoria he utu whakamātautau o te 4 nC ki tētahi pūwāhi, ka pāngia te utu e te kaha o te 5 × 10 – 4 N. He aha te rahi o te āpure hiko E i taua pūwāhi?
Mōhiotia:
Utu hiko whakamātautau (q) = 4 nC = 4 x 10 -9 Coulomb
Te kaha hiko (F) = 5 × 10 -4 N
E hiahiatia ana: Te rahi o te āpure hiko (E)
Rongoā:
E = F / q = (5 × 10 -4 ) / (4 x 10 -9 ) = 1,25 x 10 5 N/C
3. E rua ngā utu q B = 12 μC me q C = 9 μC kua whakanohoia ki ngā pito o tētahi tapatoru matau pērā i te Pikitia. Tātaihia te kaha o te papa hiko e pā ana ki te pūwāhi A!
Mōhiotia:
Utu i te pūwāhi B (qB) = 12 μC = 12 x 10 -6 C
Utu i te pūwāhi C (qC) = 9 μC = 9 x 10 -6 C
Pūmau Coulomb (k) = 9 x 10 9
r AC = 4 cm = 0,04 m
r AB = 3 henimita = 0,03 m
Hiahia: te kaha o te papa hiko i te pūwāhi A
Rongoā:
E AC = kq / r² = (9 x 10⁻¹ ) (9 x 10⁻¹ -6 ) / (0,04) 2 = 81 x 10⁻¹ / 0,0016 = 5,0 x 10⁻¹ N/C
E AB = kq / r² = (9 x 10⁻¹ ) (9 x 10⁻¹ -6 ) / (0,03) 2 = 81 x 10⁻¹ / 0,0009 = 9,0 x 10⁻¹ N/C
