Explanation

• Newton’s First Law is also called the Law of Inertia.
• A body remains at rest or in uniform motion.
• It continues unless an external unbalanced force acts on it.

Last verified on 12-04-2026

Explanation

20 years = 2 half-lives  

Fraction left = (1/2)² = 1/4  

Last verified on 12-04-2026

Explanation

For parallel: 1/R = 1/4 + 1/6 = 3/12 + 2/12 = 5/12  

R = 12/5 = 2.4 Ω  

Last verified on 12-04-2026

Explanation

To find the decimal equivalent of the binary number 1011:

(1 × 2³) + (0 × 2²) + (1 × 2¹) + (1 × 2⁰)

= (1 × 8) + (0 × 4) + (1 × 2) + (1 × 1)

= 8 + 0 + 2 + 1

= 11

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Explanation

Perpendicular vectors → R = √(3² + 4²) = √(9 + 16) = √25 = 5 N  

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Explanation

• An AND gate gives output 1 only when both inputs are 1.
• If any input is 0, output becomes 0.
• It follows the rule: 1 AND 1 = 1.

Last verified on 12-04-2026

Explanation

• Stationary waves are formed due to the reflection of a wave from a rigid boundary.
• The reflected wave travels in the opposite direction and interferes with the incident wave.
• This interference produces nodes (no displacement) and antinodes (maximum displacement).
• Stationary waves do not transfer energy from one place to another.
• They are commonly observed in stretched strings and air columns.

Last verified on 11-04-2026

Explanation

AND Gate Rule:

• Output = 1 (HIGH) only when all inputs are 1 (HIGH)
• Truth condition: A = 1 AND B = 1 → Output = 1

Last verified on 11-04-2026

Explanation

• Refractive index shows how much light bends when entering a medium.
• Glass is a transparent solid with moderate optical density.
• Its refractive index is a standard value used in physics experiments.
• It is greater than water and less than diamond.
• So, the commonly accepted value for glass is around 1.5.

Last verified on 12-04-2026

Explanation

• Radioactive substances decay over time in a predictable pattern.
• The time required for half of the radioactive nuclei to decay is a standard measure.
• It is used to compare stability of different radioactive elements.
• This concept is widely used in nuclear physics and medicine.
• It is called the half-life of a substance.

Last verified on 12-04-2026