Science- Electricity

Question 1

Parallel Circuits

Answer 1

In a parallel circuit, components are connected across common points, creating multiple paths for current to flow. Each branch has the same voltage, and the total current is the sum of the currents through each branch. The total resistance is less than the smallest resistance in the branches.

Question 2

Series Circuits

Answer 2

In a series circuit, components are connected end-to-end, forming a single path for current to flow. The total voltage is the sum of voltages across each component, and the same current flows through each component. The total resistance is the sum of individual resistances.

Question 3

Series vs Parallel circuits:
Series

Answer 3

The total voltage across the circuit is the sum of the voltages across each component. The same current flows through all components, and the total resistance is the sum of individual resistances.

Question 4

Series vs Parallel circuits:
Parallel

Answer 4

Each branch has the same voltage, but the total current is the sum of the currents through each branch. The total resistance is found using
(Equation) and is less than the smallest branch resistance.

Question 5

Define Voltage, Current, Resistance, Potential Difference.

Answer 5

Voltage: The electric potential difference between two points in a circuit, measured in volts (V).

Current: The flow of electric charge through a conductor, measured in amperes (A).

Resistance: The opposition to the flow of current, measured in ohms (Ω).

Potential Difference: Another term for voltage, it is the difference in electric potential between two points.

Question 6

Ohms Law

Answer 6

Formula:
𝑉=𝐼×𝑅
V=I×R. This formula relates voltage (V), current (I), and resistance (R). To find voltage, multiply current by resistance; to find current, divide voltage by resistance; to find resistance, divide voltage by current.

Question 7

Light Waves

Answer 7

Nature: Light waves are transverse waves, meaning the oscillations are perpendicular to the direction of travel. Light is measured by wavelength, frequency, and speed, with a speed of approximately
3×1083×108 meters per second in a vacuum. Light also exhibits particle properties as photons.

Question 8

Reflection of light

Answer 8

Reflection: The angle of incidence (the angle between the incident ray and the normal) is equal to the angle of reflection (the angle between the reflected ray and the normal).

Question 9

Refraction

Answer 9

Refraction: Refraction is the bending of light as it passes from one medium to another with different densities due to a change in its speed. This causes objects to appear distorted or closer when viewed through a different medium like water.

Question 10

Refractive index

Answer 10

Refractive Index: The refractive index (
𝑛
n) measures how much light slows down in a medium compared to its speed in a vacuum. It is calculated as (equation) where c is the speed of light in a vacuum and v is the speed in the medium.

Question 11

Colours of light

Answer 11

Primary Colors: Red, Green, and Blue are the primary colors of light.

Secondary Colors: Cyan, Magenta, and Yellow are created by mixing primary colors.

Question 12

Reflection and absorption of light

Answer 12

Opaque Objects: Opaque objects reflect or absorb different wavelengths of light, which determines their color. The color seen is the result of reflected light.

Question 13

Optical Fibres

Answer 13

Optic Fibres: Optic fibres use total internal reflection to transmit light signals over long distances with minimal loss, providing high bandwidth and low signal degradation compared to conventional wires.

Question 14

Microwave ovens

Answer 14

Microwave Ovens: Microwave ovens use microwaves to excite water molecules in food, generating heat for cooking. They are efficient for heating due to their ability to directly target water molecules.