How is a voltmeter connected in the circ | Class 10 Science Chapter Electricity, Electricity NCERT Solutions

When a 12 V battery is connected across an unknown resistor, there is a current of 2.5 mA in the circuit. Find the value of the resistance of the resistor.

Outline a project which aims to find the dominant coat colour in dogs.

Draw the structure for the following compounds.                

       (i)    Ethanoic acid             (ii)   Bromopentane*
       (iii)  Butanone                   (iv)   Hexanal.

*Are structural isomers possible for bromopentane?

A hot plate of an electric oven connected to a 220 V line has two resistance coils A and B, each of 24 Ω resistance, which may be used separately, in series, or in parallel. What are the currents in the three cases?

How is the sex of the child determined in human beings?

(a)  What property do all elements in the same column of the Periodic Table as boron have in common?
(b)  What property do all elements in the same column of the Periodic Table as fluorine have in common?

Calculate the number of electrons constituting one coulomb of charge.

A man with blood group A marries a woman with blood group O and their daughter has blood group O. Is this information enough to tell you which of the traits – blood group A or O – is dominant? Why or why not?

What is an homologous series? Explain with an example.

Why is variation beneficial to the species but not necessarily for the individual?

The refractive index of diamond is 2.42. What is the meaning of this statement?

Write equations for the reactions of

   (i) iron with steam
   (ii) calcium and potassium with water.

What changes would you suggest in your home in order to be environment-friendly?

Why are coils of electric toasters and electric irons made of an alloy rather than a pure metal?

Prepare a list of five items that you use daily in the school. Identify from the list such items that can be recycled.

Describe the flow of blood through the heart of human beings.

Why should a magnesium ribbon be cleared before burning in air?

List two advantages associated with water harvesting at the community level.

What is a good fuel?

What changes are observed in the uterus if fertilisation does not occur?