Explanation

• When a charged particle moves perpendicular to a uniform magnetic field, the magnetic force acts toward the center of its circular path.
• This magnetic force provides the centripetal force required for circular motion.
• The magnetic force is given by F=qvB when the particle moves perpendicular to the field.

Last verified on 25-10-2026

Explanation

• During one complete oscillation, the pendulum returns to its initial position, so its net change in potential energy is zero.
• The work done by the restoring force over a complete cycle is zero.
• Because the energy gained during one part of the motion is balanced by the energy lost during the other part.
• At the extreme positions, the pendulum has maximum potential energy and zero kinetic energy.
• At the mean position, its kinetic energy is maximum and potential energy is minimum.

Last verified on 25-10-2026

Explanation

Formula: v^2 = u^2 + 2gh

u = 0 (dropped)

v = 14 m/s

g = 9.8 m/s^2

14^2 = 0 + 2 x 9.8 x h fallen

196 = 19.6 x h fallen

h fallen = 10m

Height from ground = Total height - Fallen height

Height from ground = 25 - 10 = 15m

Last verified on 25-10-2026

Explanation

• Threshold frequency is the minimum frequency of light required to eject electrons from a metal surface.
• Aluminum has a higher threshold frequency than sodium because its line begins at a higher frequency.
• The slope of the kinetic energy versus frequency graph is the same for both metals because it represents Planck’s constant.

Last verified on 25-10-2026

Explanation

After 1 half-life = half remains = N/2

After 2 half-life = half of N/2 remains = N/4

Last verified on 25-10-2026

Explanation

• X-rays are also known as Roentgen rays.
• It named after German physicist Wilhelm Conrad Röntgen, who discovered them in 1895.
• X-rays are a form of electromagnetic radiation with high energy and short wavelengths.
• They can pass through soft tissues.
• The are widely used in medical imaging.

Last verified on 25-10-2026

Explanation

• Force is defined as the rate of change of linear momentum with respect to time.
• According to Newton’s second law, force causes a change in an object’s momentum.

Last verified on 25-10-2026

Explanation

• Light travels at approximately 300,000 kilometres per second in a vacuum.
• While sound travels through air at about 343 metres per second at 20°C.
• Lightning produces a flash of light and heats the surrounding air rapidly, causing the thunder we hear.
• Light reaches our eyes almost instantly over ordinary storm distances, whereas sound takes longer to reach our ears.

Last verified on 22-10-2026

Explanation

• Intermediate-focus earthquakes: occur at depths of 70–300 km.

Additional information:

• Shallow-focus earthquakes: occur at depths of 0–70 km.
• Deep-focus earthquakes: occur at depths of 300–700 km.

Last verified on 22-10-2026

Explanation

• GIS (Geographic Information System) is a computer-based system used to collect, store, analyze, and display geographically referenced data.
• Its basic output is often a map that presents spatial information visually.
• GIS maps can show roads, buildings, rivers, land use, population distribution, and service locations.
• GIS also produces tables, statistics, reports, and spatial measurements, depending on the analysis.

Last verified on 21-10-2026