Why don’t two magnetic field lines | Class 10 Science Chapter Magnetic effects of Electric Current, Magnetic effects of Electric Current 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?

Study the following cross and showing self pollination in F₁, fill in the blank and answer the question that follows

Parents            RRYY                     x                rryy
                        Round, yellow                          wrinkled, green
   F₁ —             Rr Yy                      x                ?
                        Round, yellow

Why does dry HCl gas not change the colour of the dry litmus paper?

What are the functions of gastric glands present in the wall of the stomach?

The xylem in plants are responsible for

         (a) transport of water.                   (c) transport of amino acids.
         (b) transport of food.                     (d) transport of oxygen.

How are water and minerals transported in plants?

Two lamps, one rated 100 W at 220 V, and the other 60 W at 220 V, are connected in parallel to electric mains supply. What current is drawn from the line if the supply voltage is 220 V?

What is the role of a plane mirror and a glass sheet in a solar cooker?

What is the importance of forest as a resource?

Match the words of Column (A) with that of Column (B)

Explain some harmful effects of agricultural practices on the environment.