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The value of Coulomb's constant (k) in SI units in a vacuum is approximately:

9 × 10⁻⁹N⋅m²/C².

9 × 10⁹ N⋅m²/C².

8.85 × 10⁻¹² F/m.

1.6 × 10⁻¹⁹C.

When a neutral body acquires a net positive charge, it has:

Lost protons.

Lost electrons.

Gained protons.

Gained electrons.

Which of the following pairs of forces are both non-contact forces?

Air resistance force and electrostatic force.

Magnetic force and weight.

Weight and upthrust.

Electrostatic force and friction force.

If the distance between two charges Q₁, and Q₂ is doubled, the electrostatic force of repulsion between them will:

double.

remain the same.

increase.

reduce.

According to the fundamental laws of electric charges, which statement is correct?

Like charges attract each other.

Like charges repel each other, and opposite charges attract each other.

Charged objects have no effect on neutral objects.

Opposite charges repel each other.