Explanation

The electric field due to a positive charge points away from the charge, i.e., radially outward.

Field lines show the direction a positive test charge would move.

Explanation

The energy stored in a capacitor is given by U = (1/2)CV². If the potential difference (V) is doubled:

U ∝ V²

U' ∝ (2V)² = 4V²

So, the energy stored will increase by a factor of 4.

Explanation

Given the formula and calculation:

F = qE

= (1.6 × 10⁻¹⁹ C) × (1.8 × 10⁻⁸ N/C)

= 2.88 × 10⁻¹¹ N

Explanation

Electric field intensity is defined as force per unit charge (N/C) or potential difference per unit distance (V/m).

So, V/m is an equivalent.

It is commonly used unit for electric field intensity.

Explanation

The product RC (Resistance × Capacitance) gives the time constant in an RC circuit.

Its unit is Ohm × Farad = seconds (s), which is the unit of time.

Explanation

Energy density is defined as energy per unit volume, so the SI unit is joules per cubic meter (J/m³).

It applies to electric fields where

𝑢 = 1/2𝜀𝐸², with 𝑢 being energy density.

Explanation

Joule is a derived unit of energy, not a base unit.

Kelvin (temperature), Kilogram (mass), and Ampere (current) are SI base units.

Explanation

All non-zero digits and zeros between or after decimals are significant.

In 1.00110, all six digits (1, 0, 0, 1, 1, 0) are significant.

Explanation

A colour printer uses 4 colours:

1. Cyan,
2. Magenta,
3. Yellow,
4. Black (CMYK).

These four inks mix to produce a full spectrum of printed colours.

Explanation

According to Einstein’s equation E = mc², where c = 3 × 10⁸ m/s (speed of light),

E = 1 × (3 × 10⁸)² = 9 × 10¹⁶ joules.

This shows that 1 kg of mass can be converted into 9 × 10¹⁶ joules of energy.