Skip to content
Login Register

#electron count

14 public questions tagged with this topic.

Coulomb's Law and Force Between Point Charges

A plastic rod gains a charge of \( -1.28 \times 10^{-7} \, \text{C} \) when rubbed. How many electrons were transferred

**Electrostatic force** described by F = (1/4π ε₀)·q₁q₂/r² obeys Newton's third law. Magnitude depends on q₁q₂ and 1/r², enabling quantitative estimation at given separation, with sign indicating attraction or repulsion. Negative charge means electrons gained. q = n e , e = -1.6 × 10⁻¹⁹ C . n = (q/|e|) = (1.28 × 10⁻⁷/1.6 × 10⁻¹⁹) = 8 × 10¹¹ . Substituting values gives 8 × 10¹¹, which matches expected magnitude for this electrostatic configuration, confirming Coulomb's and Gauss's principles and charge quantization consistency.

Ref: NCERT > Physics Book > Electric Charges and Fields > Coulomb's Law and Force Between Point Charges

View Details
Coulomb's Law and Force Between Point Charges

A body acquires a charge of \( -9.6 \times 10^{-8} \, \text{C} \) when rubbed. How many electrons were transferred to it

**Inverse-square law** for charges states F ∝ 1/r² while increasing with charge product. Using k = 9×10⁹ N·m²/C², force at distance r follows F = k q₁q₂/r², forming basis for pairwise force calculation. Negative charge indicates electrons gained. q = n e , e = -1.6 × 10⁻¹⁹ C . n = (q/|e|) = (9.6 × 10⁻⁸/1.6 × 10⁻¹⁹) = 6 × 10¹¹ . Substituting values gives 6 × 10¹¹, which matches expected magnitude for this electrostatic configuration, confirming Coulomb's and Gauss's principles and charge quantization consistency.

Ref: NCERT > Physics Book > Electric Charges and Fields > Coulomb's Law and Force Between Point Charges

View Details
Coulomb's Law and Force Between Point Charges

A glass rod is rubbed with silk and acquires a charge of \( +2.5 \times 10^{-7} \, \text{C} \). How many electrons were

**Inverse-square law** for charges states F ∝ 1/r² while increasing with charge product. Using k = 9×10⁹ N·m²/C², force at distance r follows F = k q₁q₂/r², forming basis for pairwise force calculation. Charge on glass rod is positive, so electrons are transferred from glass to silk. Charge of one electron e = -1.6 × 10⁻¹⁹ C . Number of electrons: n = (q/|e|) = (2.5 × 10⁻⁷/1.6 × 10⁻¹⁹) = 1.5625 × 10¹² . Substituting values gives 1.56 × 10¹², which matches expected magnitude for this electrostatic configuration, confirming Coulomb's and Gauss's principles and charge quantization consistency.

Ref: NCERT > Physics Book > Electric Charges and Fields > Coulomb's Law and Force Between Point Charges

View Details
Coulomb's Law and Force Between Point Charges

A plastic rod gains \( 4.8 \times 10^{-8} \, \text{C} \) of negative charge when rubbed. How many electrons were transfe

**Coulomb's law** gives force between point charges as F = k·|q₁q₂|/r², k = 1/(4π ε₀) = 9×10⁹ N·m²/C², directed along line joining charges. Like charges repel, opposite attract, magnitude scales with product of charges and inverse square of separation r². Negative charge means electrons are gained. q = n e , e = -1.6 × 10⁻¹⁹ C . n = (q/|e|) = (4.8 × 10⁻⁸/1.6 × 10⁻¹⁹) = 3 × 10¹¹ . Substituting values gives 3 × 10¹¹, which matches expected magnitude for this electrostatic configuration, confirming Coulomb's and Gauss's principles and charge quantization consistency.

Ref: NCERT > Physics Book > Electric Charges and Fields > Coulomb's Law and Force Between Point Charges

View Details
Electric Charge, Quantization and Conservation

A glass rod loses \( 9.6 \times 10^{-8} \, \text{C} \) of charge when rubbed with silk. How many electrons were transfer

**Fundamental property of charge** includes additivity and quantization, meaning net charge equals algebraic sum of constituents and each is multiple of e. When rod loses charge, electron removal is inferred, and n = q/e gives transferred count. Losing charge means electrons are removed, so charge is positive. q = n e , e = 1.6 × 10⁻¹⁹ C . n = (q/|e|) = (9.6 × 10⁻⁸/1.6 × 10⁻¹⁹) = 6 × 10¹¹ . Substituting values gives 6 × 10¹¹, which matches expected magnitude for this electrostatic configuration, confirming Coulomb's and Gauss's principles and charge quantization consistency.

Ref: NCERT > Physics Book > Electric Charges and Fields > Electric Charge, Quantization and Conservation

View Details
Electric Charge, Quantization and Conservation

How many electrons must be added to a neutral body to give it a charge of \( -8 \times 10^{-8} \, \text{C} \)?

**Fundamental property of charge** includes additivity and quantization, meaning net charge equals algebraic sum of constituents and each is multiple of e. When rod loses charge, electron removal is inferred, and n = q/e gives transferred count. q = n e , e = -1.6 × 10⁻¹⁹ C . n = (q/e) = (-8 × 10⁻⁸/-1.6 × 10⁻¹⁹) = 5 × 10¹¹ . Substituting values gives 5 × 10¹¹, which matches expected magnitude for this electrostatic configuration, confirming Coulomb's and Gauss's principles and charge quantization consistency.

Ref: NCERT > Physics Book > Electric Charges and Fields > Electric Charge, Quantization and Conservation

View Details