Question

llal engine operates according to the cycle shown in the P Vdiagram below. The absorbed is 1.0 mol of an ideal gas. If Ti K, and the heat eh t by this engine is 29930 J, what is the efficiency of the a 43% b 25% c 68% d 18% e 32% 6 What is the direction of the electric field at the upper right corner of the square in the figure a. Upward and to the right b. Straight to the right c. Downward and to the left d. Straight downward e, Zero +20 7 Four point charges (q uc) are fixed in position at corners of a square of side a 0.5 m as shown in the 12 the field at the center of the figure. The magnitude ofthe electric square is a 2.5 x 106 NC b 4.3 NIC c 3458 NIC d 0 NFC e 8.4 x 104 NC
Pls I need to know where the right answers they're all multiple choices

Answer 1

E_2 = 2 KQ/r^2 r = squareroot a E_2 = KQ/a^2 E_1 = KQ/a^2 = E_3 = > E_13 = squareroot 2 E_2 downward and along the diagonal. all electric fields are cancelled so total field is zero.