Class 10 Science - Chapter Magnetic effects of Electric Current NCERT Solutions | Name some devices in which electric moto

The magnetic field in a given region is uniform. Draw a diagram to represent it.

How does a solenoid behave like a magnet? Can you determine the north and south poles of a current–carrying solenoid with the help of a bar magnet? Explain.

Explain the underlying principle and working of an electric generator by drawing a labelled diagram. What is the function of brushes?

In Activity 13.7, how do we think the displacement of rod AB will be affected if (i) current in rod AB is increased; (ii) a stronger horse-shoe magnet is used; and (iii) length of the rod AB is increased?

A positively-charged particle (alpha-particle) projected towards west is deflected towards north by a magnetic field. The direction of magnetic field is

   (a) towards south                 (b) towards east
   (c) downward                       (d) upward

Draw a labelled diagram of an electric motor. Explain its principle and working. What is the function of a split ring in an electric motor?

Draw magnetic field lines around a bar magnet.

Consider a circular loop of wire lying in the plane of the table. Let the current pass through the loop clockwise. Apply the right-hand rule to find out the direction of the magnetic field inside and outside the loop.

List the properties of magnetic field lines.

Two circular coils A and B are placed closed to each other. If the current in the coil A is changed, will some current be induced in the coil B? Give reason.

Did Döbereiner’s triads also exist in the columns of Newlands’ Octaves? Compare and find out.

What is a good source of energy?

Why is diffusion insufficient to meet the oxygen requirements of multi-cellular organisms like humans?

What are trophic levels? Give an example of a food chain and state the different trophic levels in it.

What changes can you make in your habits to become more environment-friendly?

What is the difference between a reflex action and walking?

What is the importance of DNA copying in reproduction?

If a trait A exists in 10% of a population of an asexually reproducing species and a trait B exists in 60% of the same population, which trait is likely to have arisen earlier?

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

Define the principal focus of a concave mirror.

Define the principal focus of a concave mirror.

Why are the small numbers of surviving tigers a cause of worry from the point of view of genetics?

State two ways to prevent the rusting of iron.

Calculate the number of electrons constituting one coulomb of charge.

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

What are the advantages of sexual reproduction over asexual reproduction?

Why do HCl, HNO₃, etc., show acidic characters in aqueous solutions while solutions of compounds like alcohol and glucose do not show acidic character?

Use Mendeléev’s Periodic Table to predict the formulae for the oxides of the following elements:

    K,     C,      AI,      Si,      Ba.

How is food transported in plants?

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.