Current electricity

The resistance of the wire varies inversely as

• area of cross section

• resistivity

• length

• temperature

The instrument used for measuring electric current is

• galvanometer

• ammeter

• voltmeter

• potentiometer

Which is the most commonly used conductor in electrical circuits?

• copper

• aluminium

• silver

• gold

If one of the resistors in a parallel circuit is removed, the total resistance will be

• zero

• decreases

• increases

• constant

A material with negative temperature coefficient of resistance is called

• metal

• alloy

• thermistor

• thermometer

Kirchoff's first law is a consequence of conservation of

• current

• charges

• energy

• power

The melting point of tungsten is

• 3280 ^o C

• 3580 ^o C

• 3380 ^o C

• 3680 ^o C

Nichrome wire is used as the heating element beacause it has

• low specific resistance

• low melting point

• high specific resistance

• high conductivity

Thermopile works on the principle of

• Joule effect

• Peltier effect

• Thomson effect

• Seebeck effect

Positive Thomson effect is observed in

• Zinc

• Nickel

• Cobalt

• Mercury