Science Answer the questions.[Phy-1M]

Copper and aluminium are good conductors of electricity also they have low resistivity. So they are usually used for electricity transmission.

Resistance (R) of a wire is inversely proportional to its area of cross-section (A), i.e. when area of cross section increases the resistance decreases or vice versa.

In series circuits voltage is divided. Each component of a series circuit receives a small voltage so the amount of current decreases and the device becomes hot and does not work properly. Hence, series arrangement is not used in domestic circuits.

The conductors of electric heating devices such as bread toasters and electric irons are made of alloy because resistivity of an alloy is more than that of metals which produces large amount of heat.

The melting point and of Tungsten is an alloy which has very high melting point and very high resistivity so does not burn easily at a high temperature.

Electirc heater and electric fuse.

Potential difference = Current x Resistane.

Voltmeter is a high resistance device which is always connected in parallel is used to measure the voltage across a component.

Current will flow more easily through thick wire because the resistance of the thick wire will be lesser than that of thin wire.

The resistance of a voltmeter should be very large so that it takes a negligible current from the current.

The resistance of an ammeter should be very small so that it may not change the value of the current flowing in the circuit.

Electricians wear rubber hand gloves while working with electricity because rubber is an insulator and protects them from electric shocks.

Because copper and aluminium have very low resistivities.

Electric power has the unit of watt.

Electrons.

60 watt bulb, because power is inversely proportional to the resistance.

Ammeter is connected in series.

1A = 1C/ s.

An ammeter is used to measure electric current. It should be connected in series with the circuit.

Thick wire.

Electric iron, electric oven, water heater, room heater.

Heating effect.

Heating effect.

Voltmeter is used to measure p.d.

Iron.

High resistance of filament wire accounts for this difference.

Ampere.

Coulomb.

Volt.

The ratio of potential difference and current is known as resistance.

kWh is the short form of kilowatt-hour, which is the commercial unit of electrical energy.

Insulators.

Electric Current.

Nichrome is an alloy of nickel, chromium, manganese ad iron having a resistivity of about 60 times more than that of copper. It is used for making the heating elements of electrical heating appliances.

The potential difference between two points is 1 volt means 1 joule of work is done in moving 1coulomb of electric charge from one point to the other.

Electric potential at a point is 1 volt means 1 joule of work is done in moving 1 unit positive charge from infinity to that point.

An electric potential (also called the electric field potenial, potential drop or the electrostatic potential) is the amount of work needed to move a unit of charge from a Reference point to a
specific point inside the field without producing an acceleration.

Its resistance will increase.

The resistance decreases.

All the other bulbs also stop glowing.

All the other bulbs keep glowing.

Potential difference between two points in an electric circuit is defined as the amount of work done in moving a unit charge from one point to the other point.

P.d. stands for potential difference.