Explanation

• The main constituent of Permalloy is nickel-iron.
• Permalloy is a nickel-iron magnetic alloy, with about 80% nickel and 20% iron content, and is used as a magnetic core material in electrical and electronic equipment, as well as in magnetic shielding to block magnetic fields.

Explanation

The repeatable entity of a crystal structure is known as a "unit cell."

Explanation

If the radius of the Earth is reduced to one-fourth of its original value, the escape velocity will be quadrupled.

Explanation

An electric field exerts a torque on a dipole only if "the field is perpendicular to the dipole moment."

Explanation

The ball shares the train’s horizontal velocity, so it moves forward with the train.

As a result, it comes back down into the thrower’s hand.

Explanation

Force = Change in momentum / Time (from Newton’s second law).

So, change in momentum in one second is defined as force.

Explanation

The Magnus effect is a phenomenon that occurs when a spinning object moves through a fluid

The Magnus effect is named after Heinrich Gustav Magnus, the German physicist who investigated it.

Explanation

The photoelectric effect best explains the particle nature of light. 

Explanation

 A PN junction diode allows current to flow only in one direction — from P to N (forward bias).

During the positive half cycle of AC, the diode is forward-biased (low resistance), so current flows.

During the negative half cycle, the diode is reverse biased, so it blocks current and offers high resistance.

Explanation

• Resistivity (ρ) is a material property — it depends only on the type of material and its temperature.

• It does not depend on the length or cross-sectional area of the conductor.

Formula to clarify:

R=ρ⋅L/A​

• Here, $R$ is resistance, $L$ is length, $A$ is area, and $rho$ is resistivity.

• Length and area affect resistance, not resistivity.