An object is located 20.0 cm from a convex lens. The lens focuses light at a distance of 10.0 cm. What is the image distance?

A. 6.67 cm
B. -6.67 cm
C. -20.0 cm
D. 20.0 cm

The Answer Is :  D. 20.0 cm

My Reason : These types of problems can all be solved using the lens or mirror equation.

1/20 +1/q= 1/10

q=20 cm

The image is formed behind the lens at 2f or the center of curvature.

It is real, inverted, and the same size as the object

adding a(n) to an electric circuit would increase the magnetic field around a wire;

b. solenoid

a solenoid is a type of electromagnet whose purpose is to generate a controlled magnetic field.

if the purpose of the solenoid is instead to impede changes in the electric current, a solenoid can be more specifically classified as an inductor rather than an electromagnet.

  distance on the y-axis and time on the x-axis.

explanation:

the instantaneous velocity = change in position/time taken

the slope of the graph should give instantaneous velocity.

  slope of a graph = change in value of y -axis / change in values of x -axis

  comparing both the equations

    change in value of y -axis = change in position

  change in values of x -axis = time taken

so position values should be on the y axis and time values should be on the x axis.

distance on the y-axis and time on the x-axis.