c) Energy And Voltage In Circuts

Why is a parallel circuit better than series for domestic lighting?

bulbs may be switches on/off independently.

If one component breaks current ca still flow through other parts.

How does the current in a series circuit depend on applied voltage and number and nature of other components?

As voltage increase the current also increases.

The more components in a circuit the lower the current.

How does current vary with voltage in wires?

Current is proportional to voltage.

How does current vary with voltage in resistors?

Current is proportional to voltage.

How does current vary with voltage in metal filament lamps?

As current increases so does temperature increasing resistance.

How does current vary with voltage in diodes?

Current flows in one direction.

Effect of changing resistance on the current in a circuit?

As you increase resistance you’ll decrease the current due to v=ir

How does light-dependent resistors(LDR) vary with resistance?

In bright light, resistance falls.

In darkness, resistance is highest.

Useful for burglar detections.

How does a thermistor vary with resistance?

In hot conditions, resistance drops.

In cool conditions, resistance goes up.

Useful for fire alarms.

Why are lamps and LEDS useful?

They indicate the presence of a current in a circuit.

Relationship between voltage, current and resistance?

Voltage = current x resistance

Define current?

The rate of flow of charge.

Relationship between charge, current and time?

Charge = current x time

What is electric current in solid metallic conductors?

A flow of negatively charged electrons.

Why is current conserved at a junction in a circuit?

Since charge is always conserved and it takes both paths and comes back when the paths meet again.

How is the voltage in parallel circuits?

It’s the same across al branches.

How to calculate current of two components in a series circuit?

It’s the same everywhere.

IT = I1 = I2

How to calculate the voltages of two components in a series circuit?

It’s shared between each component.

VT = V1 + V2

How to calculate resistance of two components in a series circuit?

Total resistance is the sum of the resistance of each component in circuit.

RT = R1 + R2

Define voltage?

The energy transferred per unit charge passed.

Define volt?

A joule per coulomb.

Relationship between energy transferred, charge and voltage?

Energy transferred = charge x voltage