Physics Unit 1 Quiz

The distance between two consecutive peaks of a transverse wave or two consecutive compressions of a longitudinal wave.

The number of waves passing a fixed point in one second.

The speed at which a wave travels through a medium.

When a wave encounters a boundary and bounces back into the original medium.

When a wave travels from one medium to another and changes its speed and direction.

The phenomenon of a wave spreading out as it passes through a narrow opening.

A measure of how much a material slows down light.

When light travels from a denser to a rarer medium at a specific angle, and all the light is reflected back into the denser medium.

A type of lens that converges parallel light rays to a single point.

A type of lens that diverges parallel light rays.

A material that attracts iron, nickel, cobalt, and steel.

A magnet that produces its own magnetic field and retains its magnetism even when not in an external magnetic field.

A material that becomes magnetized temporarily when placed in a magnetic field.

The area surrounding a magnet where magnetic forces can be detected.

A condition where a conductor (usually a wire) comes into contact with a metal part carrying electricity, potentially leading to electrocution.

A condition where wires get too hot due to excessive current, potentially leading to fires.

The wire carrying AC current from the mains supply to the circuit.

A safety wire that prevents an appliance from becoming live, providing a low resistance path to the earth in case of a fault, preventing electrocution.

The measurement of the length of an object using a device with wheels, typically used for distances of tens of meters.

The time it takes for a person to react to a stimulus, typically measured in seconds. An average alert person takes around 0.25 seconds to react.

Taking multiple measurements of the same quantity to reduce the uncertainty in the final measurement and increase its accuracy.

The rate of change of displacement of an object, or its speed in a given direction.

A physical quantity that has both magnitude and direction. It describes the strength of an electric field at a given point.

A physical quantity that has only magnitude, not direction. It describes the rate at which energy is transferred or transformed.

The change in velocity of an object over time.

A curved line on a distance-time graph indicates that the object is accelerating.

A curved line on a speed-time graph indicates that the object is accelerating at an increasing rate.

The acceleration of an object falling freely under the influence of gravity, which is constant and independent of the object's mass. On Earth, it's approximately 9.81 m/s².

A force that opposes the motion of an object through a fluid (air or water). It increases with speed.

The measure of the quantity of matter in an object, independent of its location or gravitational field.

The force per unit mass exerted on an object in a gravitational field. It is a measure of the strength of the gravitational attraction.

A force that acts upwards on an object submerged in a fluid. It is equal to the weight of the fluid displaced by the object.

A single force that represents the combined effect of all the forces acting on an object.

The atom is mostly empty space, with a tiny, dense, positively charged nucleus at the center.

The positively charged alpha particles were repelled by the positive nucleus, causing them to change direction.

A few alpha particles bounced back, indicating a direct hit on the dense, positively charged nucleus.

An atom that has gained or lost electrons, giving it a net electrical charge.

The total number of protons and neutrons in an atom's nucleus.

The number of protons in an atom's nucleus, determining its element.

The ratio of a particle's charge to the fundamental charge (1.6 × 10^-19 C).

The relative charge of the nucleus, equal to the number of protons.

The strength of the magnetic field produced by a solenoid can be increased by increasing the frequency of rotation of the coil, increasing the number of turns on the coil, increasing the strength of the magnet, or inserting a soft iron core into the coil.

A relay is an electromagnetic switch that uses a small current to control a larger current. When a small current flows through the relay's coil, it creates a magnetic field that attracts a switch, closing contacts in a second circuit.

An electric bell works by using an electromagnet to attract and release an iron armature. This movement causes the armature to strike the bell and break the circuit, stopping the current flow and allowing the armature to return to its resting position.

In a solenoid, the end where the current flows anti-clockwise is the north pole, and the end where the current flows clockwise is the south pole.

A charged particle travelling perpendicular to a magnetic field experiences the maximum force.

A DC motor operates based on the interaction of two magnetic fields: one from the coil carrying current and the other from permanent magnets. When the current flows through the coil, it creates a magnetic field that interacts with the external field, causing the coil to rotate. By changing the direction of current flow, the rotation direction is also reversed.

A loudspeaker uses the motor effect to convert electrical signals into sound waves. An alternating current through a coil produces a magnetic field that interacts with a stationary magnet, causing the coil to vibrate. This vibration is transmitted to a diaphragm, which in turn creates compressions and rarefactions in the air, generating sound waves.

Transformers use electromagnetic induction to transfer electrical energy between two circuits without direct contact. An alternating current in the primary coil produces a changing magnetic flux that cuts through the secondary coil, inducing an alternating current in it.

Small, rocky bodies orbiting the Sun, mainly concentrated in the asteroid belt between Mars and Jupiter.

Icy bodies with highly elliptical orbits that develop tails when close to the Sun due to ice sublimation.

The force that keeps planets in orbit around the Sun and moons around planets. Stronger for larger masses and closer objects.

Planets closer to the Sun have higher orbital speeds due to stronger gravitational pull.

A stable star where nuclear fusion of hydrogen into helium occurs in the core, releasing energy.

As hydrogen runs out, the core contracts and the outer layers expand, becoming cooler (red giant or supergiant, depending on mass).

Satellites orbit the Earth at the same rate as Earth's rotation, staying above the same point, used for communication.

Satellites that pass over the Earth's poles, covering the entire surface, used for mapping and weather monitoring.