GEOLOGY

Detailed explanation-1: -The current which flows through the circuit depends upon the number of electrons flowing through the circuit per second. When using batteries, increasing the voltage also increases the current in the circuit. An increase in the current is observed when the brightness of the bulb increases.

Detailed explanation-2: -Adding a second battery to the circuit has the effect of producing a bigger push from the two batteries acting together, moving the charged particles around the circuit more quickly. This means that more charged particles per second pass any point in the circuit and so the size of the electric current is increased.

Detailed explanation-3: -Solution : In the parallel combination of light bulbs, connecting more bulbs in parallel will not affect the brightness of bulbs as voltage across each bulb still remains same and hence current ‘I=V/R‘, drawn by each bulb will remain same.

Detailed explanation-4: -Two batteries in series makes the bulb use four times as much power as one! Doubling the voltage in this arrangement both doubles the voltage drop across the resistor and the current through it. The bulb will be much brighter.

Detailed explanation-5: -As more and more light bulbs are added, the brightness of each bulb gradually decreases. This observation is an indicator that the current within the circuit is decreasing. So for series circuits, as more resistors are added the overall current within the circuit decreases.