CBSE Class 10th...

Smoking causes : 

Lenz’s law is used to find direction of :

Assertion(A): If an opaque object on the path of light becomes very small, light has a tendency to bend around it and not walk in a straight line, an effect known as the diffraction of light.

Reason(R) : To explain phenomena such as diffraction, light is thought of as wave.

Assertion(A): Small numbers of surviving tigers a cause of worry from the point of view of genetics.

Reason(R) : The experiences of an individual during its lifetime cannot be passed on to its progeny and cannot direct evolution.

A rectangular coil of copper wires is rotated in a magnetic field. In how much revolution, the direction of induced current changes once ?

The element with resistivity \(1.84\times10^{-6}\) is :

The spores are covered by thick walls that protect them until they come into contact with another moist surface and can begin to grow.

The thread- like structures that developed on the bread mould is called: 

The spores are covered by thick walls that protect them until they come into contact with another moist surface and can begin to grow.

The tiny blob-on-a-stik structures are involved in reproduction by the formation of

The spores are covered by thick walls that protect them until they come into contact with another moist surface and can begin to grow.

Spores formation is method of:

The spores are covered by thick walls that protect them until they come into contact with another moist surface and can begin to grow.

Favourable conditions for spores are:

The spores are covered by thick walls that protect them until they come into contact with another moist surface and can begin to grow.

One organism that reproduces through spore formations is:

To explain the phenomena of diffraction, light is thought of as :

Out of the given material medium, the highest refractive index is for :

The atomic numbers was adopted as the basis of modern periodic table. Prediction of properties of elements could be made with more precision when elements were arranged on the basis of increasing atomic number.

An element that has a single electron in their outermost shells belongs to

The atomic numbers was adopted as the basis of modern periodic table. Prediction of properties of elements could be made with more precision when elements were arranged on the basis of increasing atomic number.

Elements that have filled outermost shells belongs to:

The atomic numbers was adopted as the basis of modern periodic table. Prediction of properties of elements could be made with more precision when elements were arranged on the basis of increasing atomic number.

Lanthanoides series belongs to

The atomic numbers was adopted as the basis of modern periodic table. Prediction of properties of elements could be made with more precision when elements were arranged on the basis of increasing atomic number.

Out of the following elements, metal which exists in liquid form is:

The atomic numbers was adopted as the basis of modern periodic table. Prediction of properties of elements could be made with more precision when elements were arranged on the basis of increasing atomic number.

The non-metals are either solids or gases, except ......... which is liquid.

The atomic numbers was adopted as the basis of modern periodic table. Prediction of properties of elements could be made with more precision when elements were arranged on the basis of increasing atomic number.

....... metals have low densities and low melting points.

A lens that will always give a virtual, erect and diminished image, irrespective of the position of the object, is :

Asexual reproduction takes place through budding in

The speed of light is higher in a rarer medium than a denser medium. Thus, a ray of light travelling from a rarer medium (medium I) to a denser medium (medium II) slows down and bends towards the normal.

When light travels from denser medium to rarer medium, it’s speed.

The speed of light is higher in a rarer medium than a denser medium. Thus, a ray of light travelling from a rarer medium (medium I) to a denser medium (medium II) slows down and bends towards the normal.

The ratio of speeds in medium I and medium II is called:

The speed of light is higher in a rarer medium than a denser medium. Thus, a ray of light travelling from a rarer medium (medium I) to a denser medium (medium II) slows down and bends towards the normal.

Absolute refractive index is defined as:

The speed of light is higher in a rarer medium than a denser medium. Thus, a ray of light travelling from a rarer medium (medium I) to a denser medium (medium II) slows down and bends towards the normal.

Angle of deviation \((\delta)\) for light travelling from rarer to denser medium is given as:

The speed of light is higher in a rarer medium than a denser medium. Thus, a ray of light travelling from a rarer medium (medium I) to a denser medium (medium II) slows down and bends towards the normal.

In comparing two media, the one with the larger refractive index is

An alloy of lead and tin, which has a low melting point and is used for welding electrical wires together, is :

An element reacts with oxygen to give a compound with a high melting point. This compound is also soluble in water. The element is likely to be

We need not feel powerless or overwhelmed by the scale of the problems because there are many things, we can do to make a difference. Five R’s can help us to save the environment. Five R’s: refuse, reduce, reuse, repurpose and recycle.

Recycle includes:

We need not feel powerless or overwhelmed by the scale of the problems because there are many things, we can do to make a difference. Five R’s can help us to save the environment. Five R’s: refuse, reduce, reuse, repurpose and recycle.

Repurpose signifies

We need not feel powerless or overwhelmed by the scale of the problems because there are many things, we can do to make a difference. Five R’s can help us to save the environment. Five R’s: refuse, reduce, reuse, repurpose and recycle.

Sustainable development means:

We need not feel powerless or overwhelmed by the scale of the problems because there are many things, we can do to make a difference. Five R’s can help us to save the environment. Five R’s: refuse, reduce, reuse, repurpose and recycle.

Economic development is linked to:

We need not feel powerless or overwhelmed by the scale of the problems because there are many things, we can do to make a difference. Five R’s can help us to save the environment. Five R’s: refuse, reduce, reuse, repurpose and recycle.

We need to use our resources carefully because:

Food cans are coated with tin and not with zinc because :