Thin lenses: A thin converging lens is found to form an image of a distant building 24 cm from the lens. If an insect is now placed 16 cm from this lens, how far FROM THE INSECT will its image be formed?

Internal battery resistance: What is the maximum current that can be drawn from a 1.50-V battery with an internal resistance of 0.30 ohm?

Capacitors in combination: Three capacitors are connected as shown in the figure. What is the equivalent capacitance between points a and b?

Spherical mirrors: The image of a plant is 4.0 cm from a concave spherical mirror having a radius of curvature of 10 cm. Where is the plant relative to the mirror?

Thin lenses: An object is placed in front of a lens which forms an image of the object.

Reactance: The inductor in a radio receiver carries a current of amplitude 200 mA when a voltage of amplitude 2.40 V is across it at a frequency of 1400 kHz. What is the value of the inductance?

Refraction at a curved surface: A goldfish bowl is spherical, 8.0 cm in radius. A goldfish is swimming 3.0 cm from the wall of the bowl. Where does the fish appear to be to an observer outside? The index of refraction of water is 1.33. Neglect the effect of the glass wall of the bowl.

Solenoids: Consider a solenoid of length L, N windings, and radius b (L is much longer than b). A current I is flowing through the wire. If the length of the solenoid became twice as long (2L), and all other quantities remained the same, the magnetic field inside the solenoid would

Force on parallel wires: The figure shows three long, parallel, current-carrying wires. The current directions are indicated for currents I1 and I3. The arrow labeled F represents the net magnetic force acting on current I3. The three currents have equal magnitudes. What is the direction of the current I2?

Electric field and potential: If the electric potential in a region is given by V(x) = 6/x2, the x component of the electric field in that region is