Read the following and answer any four questions from (i) to (v).

No matter how far you stand from a mirror, your image appears erect. The mirror is likely to be

A child is standing in front of a magic mirror. She finds the image of her head bigger, the middle portion of her body of the same size and that of the legs smaller. The following is the order of combinations for the magic mirror from the top.

To get an image larger than the object, one can use

A convex mirror has wider field of view because

Read the following and answer any four questions from (i) to (v).
The spreading of light by the air molecules is called scattering of light. The light having least wavelength scatters more. The sun appears red at sunrise and sunset, appearance of blue sky it is due to the scattering of light. The colour of the scattered light depends on the size of particles. The smaller the molecules in the atmosphere scatter smaller wavelengths of light. The amount of scattering of light depends on the wavelength of light. When light from sun enters the earth’s atmosphere, it gets scattered by the dust particles and air molecules present in the atmosphere. The path of sunlight entering in the dark room through a fine hole is seen because of scattering of the sun light by the dust particles present in its path inside the room.

Q1.To an astronaut in a spaceship, the colour of earth appears

At the time of sunrise and sunset, the light from sun has to travel.

The colour of sky appears blue, it is due to the

At the time of sunrise and sunset

The danger signs made red in colour, because

When electric current flows through the circuit this electrical energy is used in two ways, some part is used for doing work and remaining may be expended in the form of heat. We can see, in mixers after using it for long time it become more hot, fans also become hot after continuous use. This type of effect of electric current is called as heating effect of electric current. If I is the current flowing through the circuit then the amount of heat dissipated in that resistor will be H = VIt
This effect was discovered by Joule, hence it is called as Joule’s law of heating.

How is electric power defined in an electric circuit?

What material is commonly used for filaments in electric bulbs due to its high melting point?

What is the name of the effect where electric current causes heating in a circuit?

The change in electric current through the circuit produces magnetic field around it. Magnetic field is a vector quantity which has both magnitude as well as direction. The magnetic field lines produced are directed from north pole and ends at south pole. These lines are closed curves from which strength of the magnetic field is determined. Where magnetic field lines are crowded magnetic field is stronger and where very apart the strength of magnetic field is weak. So, we can say that as the current through the electrical circuit increase then the magnitude of magnetic field also increases. If a current carrying conductor is holded in right hand by curling figures around it. Then, the curled figures gives the direction of electric current and curled figures gives the direction of magnetic field.

How are magnetic field lines oriented around a current-carrying conductor?

What determines the strength of the magnetic field around a current-carrying conductor?

What device is used to produce a strong magnetic field by winding insulated copper wire into a cylindrical shape?

What is the main application of solenoids?