Explanation

Authoritative knowledge is often trusted (reliable) but may also be contingent on context.

It is usually passed down through generations and is a significant source in cultures and education.

Explanation

Educational psychology aids in understanding how students learn and how to address their individual needs.

It helps in handling teaching difficulties, enhancing learning, and supporting slow learners effectively.

Explanation

The phrase "Expected children" typically refers to children who develop at a typical pace without requiring specialized interventions. These children:

• Can integrate into mainstream classrooms.
• Do not need special education facilities (though inclusive education benefits all).
• Follow standard developmental milestones.

Explanation

The decision-making process inherently involves multiple specific and varied activities, such as:

• Information gathering (research, data analysis)
• Evaluation of alternatives (pros/cons, risk assessment)
• Implementation (action plans, monitoring)
• Review (feedback loops, adjustments)

Explanation

Students are the primary focus and main beneficiaries of elementary education.

Schools aim to develop their basic skills, knowledge, and character at an early stage.

Explanation

The speed of sound in steel at 20°C is approximately 5100–5200 m/s, with 5130 m/s being a widely accepted value.

Sound travels faster in solids like steel due to their high density and elasticity compared to gases and liquids.

Explanation

Concave mirrors focus light into a strong, parallel beam, making them ideal for headlights and searchlights.

They reflect light from the bulb placed at their focus point, projecting it forward efficiently.

Explanation

A hand drill uses two mutually perpendicular gears to convert rotary motion.

This mechanism increases torque and helps in efficient drilling.

Explanation

A moving car possesses kinetic energy due to its motion.

Kinetic energy depends on the mass and speed of the object.

Explanation

Polythene is a polymer made by linking many ethene (ethylene) monomers.

It is widely used in plastic bags and packaging materials.