The emf of a battery is equal to its terminal potential difference: O under all conditions ○ only when the battery is being charged only when a large current is in the battery only when there is no current in the battery O under no conditions

In Figure 27-40, the resistances are R₁ = 1.20 2, R2 = 1.80 2, and the ideal batteries have emfs 1 = 2.0 V, and 2 = E3 = 5.0 V. R₁ R₁ a R₂ જ્જ R₁ 182 R₁ (a) What is the current through each battery? (Take upward to be positive.) battery 1 battery 2 battery 3 (b) What is the potential difference Va - Vb? Fig. 27-40

When a material has a negative temperature coefficient of resistance, O It has a negative resistance value at any temperature. An increase in temperature results in a decrease in resistance. It must be a conductor. O All of these

An initially uncharged parallel plate capacitor is connected to a circuit containing a battery with emf 8-42V and a resistor, R = 4.9MQ as shown in the figure to below. The capacitor whose plates have an area of A = 7.1mm² are separated by a distance of d = 5mm and one third of the capacitor is filled with a dielectric material, K₁ = 3.5 and the rest (two thirds) is filled with another dielectric material, K₂ = 3.4. At t=0 the switch is closed. 5.4 seconds after the switch is closed the electric field within the first dielectric material (K₁) is observed to be 18 × 106 N/C. Find the charge on the capacitor at this instant (t = 5.4s) in terms of permitivity of free space €0? Express your answer using zero decimal place. R E Answer: S K1 K2