Six infinitely large and thin non-conducting sheets are fixed in configurations I and II. As shown in the figure, the sheets carry uniform surface charge densities which are indicated in terms of 0. The separation between any two consecutive sheets is 1 . The various regions between the sheets are denoted as 1, 2, 3, 4 and 5. If 0=9 C/m2, then which of the following statements is/are correct: (Take permittivity of free space 0=9 10-12 F/m) [figure]
- In region 4 of the configuration I, the magnitude of the electric field is zero.
- In region 3 of the configuration II, the magnitude of the electric field is 0 0.
- Potential difference between the first and the last sheets of the configuration I is 5 V.
- Potential difference between the first and the last sheets of the configuration II is zero.
Answer
(1) In region 4 of the configuration I, the magnitude of the electric field is zero.
Solution
Field between sheets: E= 12 0 ( left- right ) (towards right). Here 0 0=106 V/m and gap =10-6 m.
Config I: regions 1, 3, 5: E= 0 0; regions 2, 4: E=0. (A) correct.
VI=3 106 10-6=3 V, not 5 V. (C) wrong.
Config II: regions 1, 3, 5: E=+ 02 0; regions 2, 4: E=- 02 0. So region 3 has 02 0. (B) wrong.
VII=(3-2) 02 0 10-6=0.5 V 0. (D) wrong.
Answer: (A)