13. The following are field forces except: * Gravitational force O Friction force O Electric force O Magnetic force 14. Two resistors R=50 and R=80 are connected in parallel circuit, how much is * the total resistance of the circuit? O 130 ohms 0.03 ohms 30.77 ohms 30 ohms15. The following must be considered when choosing the ideal gaussian surface * except: The gaussian surface must enclose some charges The Gaussian surface must have symmetry The Gaussian surface must either be a sphere or a cylinder O The gaussian surface must be a closed surface 16. Which of the following is not true about Gauss's law? * The Gauss's law holds true regardless of the shape of the gaussian surface The Gauss's law holds true regardless of the size of the gaussian surface O The gauss' law holds true regardless of the gaussian surface not being a closed surface O The gauss'law holds true regardless of what location the charges are placed inside the Gaussian surface17. What is the electric field in the Gaussian surface shown below? (inside a hollow sphere of charges) Gaussian surface P R g O Zero O Option 2\f