In Figure 7.4 (a), (b) and (c), which ap | Class 10 Science Chapter Control and Coordination, Control and Coordination 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?

Hydrogen has been used as a rocket fuel. Would you consider it a cleaner fuel than CNG? Why or why not?

Define the following terms.

   (i) Mineral          (ii) Ore          (iii) Gangue

Explain the phenomenon of dispersion of white light through a glass prism, using suitable ray diagram.

How would you distinguish experimentally between an alcohol and a carboxylic acid?

Explain the nature of the covalent bond using the bond formation in CH₃Cl.

What criteria do we use to decide whether something is alive?

Differentiate between inherited and acquired characters. Give one example for each type.

Write an equation to show the reaction between Plaster of Paris and water.

Is the chromosome number of zygote, embryonal cells and adult of a particular organism always constant? How is the constancy maintained in these three stages?

The gap between two neurons is called a

(a) dendrite.
(b) synapse.
(c) axon.
(d) impulse.