Q7 of 19 Page 60

Give Scientific reasons.

In practice, the unit kWh is used for the measurement of electrical energy, rather than joule.

As joule is a very small unit of energy but kWh is a large unit of measuring electrical energy so in practice the unit kWh is used for the measurement of electrical energy, rather than joule.


1 kWh = 3.6 × 106 J


More from this chapter

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7

Give Scientific reasons.

In the electric equipment producing heat e.g. iron, electric heater, boiler, toaster etc, an alloy such as Nichrome is used, not pure metals.

 7

Give Scientific reasons.

For electric power transmission, copper or aluminum wire is used.

 8

Which of the statement given below correctly describes the magnetic field near a long, straight current-carrying conductor?

a. The magnetic lines of force are in a plane, perpendicular to the conductor in the form of straight lines.


b. The magnetic lines of force are parallel to the conductor on all the sides of the conductor.


c. The magnetic lines of force are perpendicular to the conductor going radially outward.


d. The magnetic lines of force are in concentric circles with the wire as the center, in a plane perpendicular to the conductor.

 9

What is a solenoid? Compare the magnetic field produced by a solenoid with the magnetic field of a bar magnet. Draw neat figures and name various components.