Electric pressure is also called

The substances which have a large number of free electrons and offer a low resistance are called

Out of the following which is not a poor conductor ?

Out of the following which is an insulating material ?

The property of a conductor due to which it passes current is called

Conductance is reciprocal of

With rise in temperature the resistance of pure metals

With rise in temperature the resistance of semi-conductors

The resistance of a copper wire 200 m long is 21 Q. If its thickness (diameter) is 0.44 mm, its specific resistance is around

An instrument which detects electric current is known as

In a circuit a 33 Q resistor carries a current of 2 A. The voltage across the resistor is

A light bulb draws 300 mA when the voltage across it is 240 V. The resistance of the light bulb is

The resistance of a parallel circuit consisting of two branches is 12 ohms. If the resistance of one branch is 18 ohms, what is the resistance of the other ?

Four wires of same material, the same cross-sectional area and the same length when connected in parallel give a resistance of 0.25 Q. If the same four wires are connected is series the effective resistance will be

A current of 16 amperes divides between two branches in parallel of resistances 8 ohms and 12 ohms  espectively. The current in each branch is

Current velocity through a copper conductor is

Which of the following material has nearly zero temperature co-efficient of resistance?

You have to replace 1500 Q resistor in radio. You have no 1500 Q resistor but have several 1000 Q ones which you would connect

Two resistors are said to be connected in series when

Which of the following statement is true both for a series and a parallel D.C. circuit?

Which of the following materials has a negative temperature co-efficient of resistance?

Ohm’s law is not applicable to

Which is the best conductor of electricity ?

For which of the following ‘ampere second’ could be the unit ?

All of the following are equivalent to watt except

A resistance having rating 10 ohms, 10 W is likely to be a

Which one of the following does not have negative temperature co-efficient ?

Insulating materials have the function of

The rating of a fuse wire is always expressed in

In a series circuit with unequal resistances

The filament of an electric bulb is made of

A 3 Q resistor having 2 A current will dissipate the power of

Which of the following statement is true?

The resistance of a few meters of wire conductor in closed electrical circuit is

If a parallel circuit is opened in the main line, the current

If a wire conductor of 0.2 ohm resistance is doubled in length, its resistance becomes

Three 60 W bulbs are in parallel across the 60 V power line. If one bulb burns open

The four bulbs of 40 W each are connected in series swift a battery across them, which of the following statement is true ?

Two resistances Rl and Ri are connected in series across the voltage source where Rl>Ri. The largest drop will be across

A closed switch has a resistance of

The hot resistance of the bulb’s filament is higher than its cold resistance because the temperature co-efficient of the filament is

The insulation on a current carrying conductor is provided

The thickness of insulation provided on the conductor depends on

Which of the following quantities remain the same in all parts of a series circuit ?

A 40 W bulb is connected in series with a room heater. If now 40 W bulb is replaced by 100 W bulb, the heater output will

In an electric kettle water boils in 10 m minutes. It is required to boil the boiler in 15 minutes, using same supply mains

An electric filament bulb can be worked from

Resistance of a tungsten lamp as applied voltage increases

Electric current passing through the circuit produces

If the efficiency of a machine is to be high, what should be low ?

When electric current passes through a metallic conductor, its temperature rises. This is due to

Two bulbs of 500 W and 200 W rated at 250 V will have resistance ratio as

A glass rod when rubbed with silk cloth is charged because

Whether circuit may be AC. or D.C. one, following is most effective in reducing the magnitude of the current.

When one leg of parallel circuit is opened out the total current will

In a lamp load when more than one lamp are switched on the total resistance of the load

Two lamps 100 W and 40 W are connected in series across 230 V (alternating). hich of the following statement is correct ?

Resistance of 220 V, 100 W lamp will be

In the case of direct current

When electric current passes through a bucket full of water, lot of bubbling is observed. This suggests that the type of supply is

Resistance of carbon filament lamp as the applied voltage increases.

Bulbs in street lighting are all connected in

For testing appliances, the wattage of test lamp should be

Switching of a lamp in house produces noise in the radio. This is because switching operation produces

Sparking occurs when a load is switched off because the circuit has high

Copper wire of certain length and resistance is drawn out to three times its length without change in volume, the new resistance of wire becomes

When resistance element of a heater fuses and then we reconnect it after removing a portion of it, the power of the heater will

A field of force can exist only between

A substance whose molecules consist of dissimilar atoms is called

International ohm is defined in terms of the resistance of

Three identical resistors are first connected in parallel and then in series. he resultant resistance of the first combination to the second will be

Which method can be used for absolute measurement of resistances ?

Ohm’s law is not applicable to

Two copper conductors have equal length. The cross-sectional area of one conductor is four times that of the other. If the conductor having smaller cross-sectional area has a resistance of 40 ohms the resistance of other conductor will be

A nichrome wire used as a heater coil has the resistance of 2 £2/m. For a heater of 1 kW at 200 V, the length of wire required will be

Temperature co-efficient of resistance is expressed in terms of

When current flows through heater coil it glows but supply wiring does not glow because

The condition for the validity under Ohm’s law is that

. Which of the following statement is correct ?

. A rheostat differs from potentiometer in the respect that it

. The weight of an aluminium conductor as compared to a copper conductor of identical cross-section, for the same electrical resistance, is

. An open resistor, when checked with an ohm-meter reads

. are the materials having electrical conductivity much less than most of the metals but much greater than that of typical insulators.

. All good conductors have high

. Voltage dependent resistors are usually made from

. The ratio of mass of proton to that of electron is nearly

. The number of electrons in the outer most orbit of carbon atom is

. With three resistances connected in parallel, if each dissipates 20 W the total power supplied by the voltage source equals

. A thermistor has

. If/, R and t are the current, resistance and time respectively, then according to Joule’s law heat produced will be proportional to

. Nichrome wire is an alloy of

. When a voltage of one volt is applied, a circuit allows one micro ampere current to flow through it. The conductance of the circuit is

. Conductance : mho ::

. One newton meter is same as