HSC Science Class 12 - Tamil Nadu Board of Secondary Education Question Bank Solutions

Define the work function of a metal. Give its unit.

What are the shapes of wavefront for source at infinite?

What do you mean by electron emission? Explain briefly various methods of electron emission.

I₀ is the intensity of light existing between two cross Polaroids kept with their axes perpendicular to each other. A third polaroid is introduced between them. What must be the angle between the axes of the first and the newly introduced polaroid to get the maximum light from the whole arrangement?

A 150 W lamp emits light of the mean wavelength of 5500 Å. If the efficiency is 12%, find out the number of photons emitted by the lamp in one second.

Name some equipment that uses electromagnetism for functioning.

Sea turtles return to their birth beach many decades after they were born due to ______.

A wire connected to a power supply of 230 V has power dissipation P₁. Suppose the wire is cut into two equal pieces and connected parallel to the same power supply. In this case, power dissipation is P₂. The ratio of `"P"_2/"P"_1` is

Define Current density.

State microscopic form of Ohm’s law.

State macroscopic form of Ohm’s law.

What is ohmic device?

What is non ohmic device?

Define temperature coefficient of resistance.

Write a short note on superconductors?

Obtain the macroscopic form of Ohm’s law from its microscopic form and discuss its limitation.

Explain the equivalent resistance of a series resistor network.

Explain the equivalent resistance of a parallel resistor network.

The resistance of a nichrome wire at 0°C is 10Ω. If its temperature coefficient of resistivity of nichrome is 0.004/ °C, find its resistance of the wire at boiling point of water. Comment on the result.

An electronics hobbyist is building a radio which requires 150 Ω in her circuit, but she has only 220 Ω, 79 Ω, and 92 Ω resistors available. How can she connect the available resistors to get the desired value of resistance?