3. As shown in the figure, I and II are the divergent rays of the light source s (not shown in the figure) on the principal axis PQ of the lens after being refracted by the lens. In the figure, l is the position of the lens, O is the optical center of the lens, and m is the intersection point of the opposite extension lines of the two rays () A. if the luminous point s is on M, the transparent mirror is a convex lens B. if the luminous point s is on the left side of M, If s is on the right side of M, the lens is convex D. lens L must be concave

3. As shown in the figure, I and II are the divergent rays of the light source s (not shown in the figure) on the principal axis PQ of the lens after being refracted by the lens. In the figure, l is the position of the lens, O is the optical center of the lens, and m is the intersection point of the opposite extension lines of the two rays () A. if the luminous point s is on M, the transparent mirror is a convex lens B. if the luminous point s is on the left side of M, If s is on the right side of M, the lens is convex D. lens L must be concave

Choose C because the intersection point of the reverse extension line is m, so if the convex lens forms an upright enlarged virtual image, like in the back of the object, then M is higher than s, and M is on the left side of S, that is to say, s is lower than m, and S is on the right side of M. of course, if the concave lens forms an upright reduced virtual image, like in the left side of the object, then s is higher than m, and S is not on the left side of M!

On the same equipotential surface, does the greater the charge quantity of the same charge, the greater the potential energy

No, the electric potential energy is equal to the electric potential multiplied by the amount of charge. The greater the amount of charge on the same equipotential surface, the greater the absolute value of the electric potential energy. However, it involves positive and negative problems, such as 1C for a charged particle on the equipotential surface with the potential of - 1V and 2C for the other. The former has a potential energy of - 1J and the latter is - 2J. The former has a smaller charge but a larger potential energy

For the two experiments of "exploring the relationship between current and resistance" and "measuring resistance by voltammetry", the following statement is correct ()
A. They all adopt the research method of control variables. B. their experimental circuits are the same in textbooks. C. The purpose of the former is to analyze multiple groups of data and get the relationship between current and resistance. D. The purpose of the latter is to take the average value of resistance and reduce the error

A. In "exploring the relationship between current and resistance", we need to use the control variable method, while in "voltammetric measurement of resistance", we don't need to use the control variable method, which is incorrect and does not conform to the meaning of the topic; B. the experimental circuit diagrams of the two experiments are the same, which is correct and consistent with the meaning of the topic; in order to reduce the error in the experimental process, we often use the method of multiple measurements to get the average value for analysis and solution So CD is correct, in line with the meaning of the topic; so choose B, C, D