Current Electricity Exam Review

These flashcards cover key concepts and calculations related to current electricity, as outlined in the lecture notes.

What does an emf of 5.30 V mean for a battery?

It means the battery can provide a voltage of 5.30 volts when no current is drawn.

How can the reading on the ammeter be shown to be approximately 7 mA with the given circuit?

Using Ohm's Law and the voltage reading from the voltmeter and resistance of components.

What is the resistance R of the voltmeter when it is approximately 300 Ω?

The resistance of the voltmeter is found based on its reading across different resistances.

What is the power dissipated in the voltmeter?

Power is calculated using the voltage across it and its resistance.

Why does the sum of voltmeter readings across multiple resistors not equal the emf of the battery?

Because of the internal resistance of the battery and possible loading effects.

What is the new reading on the ammeter when the resistance is changed to 5 Ω?

The new ammeter reading can be calculated using the new resistance and emf.

How to determine the magnitude of the frictional force on a block being transported?

By applying Newton's second law during acceleration and using the mass and acceleration.

What are the characteristics of LDR resistance concerning light intensity?

LDR resistance decreases as light intensity increases.

What happens to the current when a light beam is broken on an LDR?

The current increases, triggering an alarm due to an increase in resistance.

How does the resistance of a filament lamp change with temperature and power?

The resistance increases with temperature due to increased thermal vibrations of the lattice.