Explanation

In the relation E = F/q , the charge q is always positive.

Explanation

If a positive charge is placed between two negative charges, the system will be unstable due to the repulsive forces between like charges.

Explanation

If the radius is doubled and the angular velocity remains constant, the tangential acceleration will be unchanged.

Explanation

If the lift is accelerated downward, the apparent weight experienced by an object inside the lift is m(g−a).

Explanation

The velocity required to put a satellite into orbit around the Earth is approximately 7.8 km/s.

Explanation

If the current is into the page and the wire is perpendicular to the page, then the magnetic field will be directed counterclockwise.

Explanation

If the radii of two droplets are in the ratio of 2:3, then their terminal velocities will be in the ratio of the inverse square of their radii. Since the terminal velocity is proportional to the square of the radius, the ratio will be:

(3/2)2 : (2/3)2 = 9/4 : 4/9.

Explanation

If the length of a solenoid is doubled, and the current passing through it is increased 9 times, the magnetic field inside the solenoid will increase by 18 times.

Explanation

When the current passing through an inductor is increased by 100 times, the energy stored in the inductor will increase by 10,000 times.

Explanation

The relationship between voltage and current in a purely resistive circuit is that voltage and current are in phase.