Explanation

An electric field does work on a charge, causing it to gain or lose energy (kinetic or potential).

A magnetic field can change the direction of a moving charge.

Explanation

In a solid metal conductor, electric current is due to the flow of free electrons.

Electrons are negatively charged particles that move through the metal to create current.

Explanation

1 kilowatt hour (kWh) = 3.6 million joules (3.6 × 10⁶ J)

1 joule = 10⁷ ergs, so both joule and erg are much smaller than kilowatt hour.

Hence, Kilowatt hour is the biggest unit.

Explanation

Explanation

In an oscillating LC circuit, the maximum energy stored in the capacitor during one cycle is equal to the total stored energy (U) in the circuit.

This is because the total energy oscillates between the capacitor and the inductor, with the total energy remaining constant in an ideal, lossless LC circuit.

Explanation

• Charge: Q=1mC=1×10^−3C

• Voltage: $V = 100,text{V}$

• The formula for capacitance is:

C=Q/V​

Calculation:

$$C = frac{1 times 10^{-3}}{100} = 1 times 10^{-5},text{F} = 10,mutext{F}$$

Explanation

The standard SI unit for magnetic dipole moment is the ampere-square meter (A⋅m²).

It can also be expressed in terms of energy and magnetic field strength, resulting in joules per tesla (J/T), which is equivalent to A⋅m². 

Explanation

When a dipole with dipole moment $vec{p}$ is placed in an external electric field $vec{E}$, the torque experienced by the dipole is given by:

$$vec{tau} = vec{p} times vec{E}$$

This is a vector cross product, so:

• The magnitude is $tau = pE sintheta$

• The direction is perpendicular to both p​ and E (using the right-hand rule)

Explanation

• Heat has the same units as work, energy, and enthalpy

Standard Units

• Joule (J): Standard SI unit for heat, work, and energy.
• Calorie (cal): Metric unit for heat and food energy
• Newton-meter (N·m): Mechanical unit equivalent to a Joule.

Explanation

In a conductor, the electric field inside the conductor (in the material itself) must be zero. So:

The inner surface of the shell must carry a charge that exactly cancels the field from the charge inside the cavity.

Since there's a –3 C charge at the center, the inner surface must have a charge of +3C to neutralize the field inside the conductor.