Explanation

• An iron nail/steel rod can be magnetized by passing an electric current around it, a process known as electromagnetic induction.
• This is the principle behind electromagnets.

Explanation

• Lever, pulley, wedge, wheel, inclined plane, and screw are examples of simple machines.
• These are basic machines that change the direction or magnitude of a force, making it easier to lift, move, or apply force to an object.

There are six types of simple machines:

1. Inclined Plane
2. Lever
3. Wheel and Axle
4. Pulley
5. Wedge
6. Screw

Explanation

• A periscope requires a prism that can reflect light by 90 degrees, allowing the user to see around obstacles or over walls.
• An isosceles right-angled prism, also known as a 45-degree prism, is ideal for this purpose.
• It has two equal sides and a 90-degree angle between them, which allows for total internal reflection and a clear image.

Explanation

• The Hall voltage (VH) is directly proportional to the magnetic flux density (B) and the current (I) flowing through the conductor, as well as the Hall coefficient (RH) of the material.
• The relationship is given by the formula: VH = RH × B × I

Explanation

Explanation

Explanation

• Tungsten is very resistant to corrosion and has the highest melting point (melting point = 3695 K) and the highest tensile strength of any element.
• Tungsten is used for making bulb filaments of incandescent lamps because it has the highest melting point and does not melt even while it is glowing for long hours.

Explanation

One degree of latitude is approximately 111 km everywhere, but it varies slightly: about 110.6 km at the equator and 111.7 km at the poles.

Lines of longitude, or meridians, run north-south.

Explanation

Commutators and brushes are recommended for high DC voltage generators because they produce sparks.

This happens due to the intermittent contact, which helps in maintaining unidirectional current flow but requires careful management to avoid excessive sparking and wear.

Explanation

In a gasoline vehicle, a capacitor/spark plug tends to prevent an arc at the contacts.

The capacitor is often part of the ignition system.

It helps suppress electrical noise and ensures smoother operation of the ignition system by minimizing arcing.