The amount of work done in forming a soap film of

size 10 cm x 10 cm is (Surface tension T= 3 x 10-2 Nm (a)6 x 10-4 j                                     (b) 3 x 10-4 j (c) 6 x 10-3 j                              d) 3 x 10-4 j Ans. a (10)