Science 9 Fourth Quarter Examination

Front

What is Ohm's Law?

Back

Ohm's Law states that the current (I) through a conductor between two points is directly proportional to the voltage (V) across the two points and inversely proportional to the resistance (R) of the conductor. It can be expressed as V = I × R.

Front

What is the formula to calculate voltage across a resistor?

Back

Voltage (V) = Current (I) × Resistance (R).

Front

What is the difference between scalar and vector quantities?

Back

Scalar quantities have only magnitude (e.g., mass, temperature), while vector quantities have both magnitude and direction (e.g., velocity, force).

Front

Define velocity in physics.

Back

Velocity is a vector quantity that refers to the rate at which an object changes its position. It includes both speed and direction.

Front

What is a permanent magnet?

Back

A permanent magnet is a material that maintains a persistent magnetic field without the need for an external power source.

Front

How can you demagnetize a permanent magnet?

Back

You can demagnetize a permanent magnet by heating it to a high temperature, which disrupts the alignment of its magnetic domains.

Front

What device converts electrical energy into mechanical energy?

Back

An electric motor converts electrical energy into mechanical energy.

Front

What happens when a bar magnet is broken into two pieces?

Back

Each piece acts as a complete magnet with its own north and south poles.

Front

What is the unit of electrical resistance?

Back

The unit of electrical resistance is the Ohm (Ω).

Front

What is the relationship between current, voltage, and resistance?

Back

The relationship is defined by Ohm's Law: V = I × R.