Explanation

• Iron is a ferromagnetic material, which means it is strongly attracted to magnets.
• Therefore, an iron kettle will be attracted to a magnet.

Explanation

Electrons are accelerated by voltages up to 10^9 V in order to find the internal structure of a nucleus.

Explanation

• Radioactivity was discovered by Henri Becquerel, a French physicist, in 1896.
• He discovered this when he was studying uranium and noticed that it emitted radiation without an external source of energy.
  
• The term radioactivity was coined by Marie Curie, who, along with her husband, investigated this phenomenon.
• Rutherford, a British physicist, studied the properties of radioactive decay and named the particles alpha, beta and gamma.

Explanation

The average translational kinetic energy of molecules is directly proportional to the temperature (in Kelvin).

Since the temperature is increased from 300 K to 750 K, the average translational kinetic energy will also increase by a factor of 750/300 = 2.5.

So, the average translational energy at 750 K will be:

6 x 10^-20 J x 2.5 = 1.5 x 10^-19 J

Explanation

When a dielectric sheet is placed between two charges, the electrostatic force between them will "decrease" because the presence of the dielectric reduces the electric field strength between the charges, thus decreasing the force experienced by them.

Explanation

Mass is a measure of an object's inertia — its resistance to changes in motion.

Unlike weight (which depends on gravity), mass is an intrinsic property and directly related to inertia.

Explanation

Explanation

For most metals, the temperature coefficient of resistance is positive, meaning that as the temperature increases, the resistance of the metal also increases.

This behavior occurs because, at higher temperatures, the metal atoms vibrate more, leading to more collisions with the electrons flowing through the material, which increases resistance.

Thus, the temperature coefficient of resistance for metals is positive.

Explanation

The Swinburne's Test is used for a no-load test on a DC motor.

It helps determine the motor's losses and efficiency under no-load conditions.

Explanation

• Scientists who forecast weather by continuously tracking and predicting the path of tornadoes, hurricanes, or floods are called Meteorologists.
• Meteorologists use computer models, satellite data, and other tools to predict weather patterns and warn people of severe weather events.
• It helping to protect lives and property.