The p.d. across a 3 ohm resistor is 6 V. The current flowing in the resistor wil be:

An electrical appliance has a resistance of 25 ohm. When this electrical appliance is connected to a 230 V supply line, the current passing through it will be:

A current of 5 amperes flows through a wire whose ends are at a potential difference of 3 volts. Calculate the resistance of the wire.

Keeping the p.d. constant, the resistance of a circuit is halved. The current will become:

A p.d. of 10V is needed to make a current of 0.02A flow through a wire. What p.d. is needed to make a current of 250 mA flow through the same wire?

The area of cross section of a wire is doubled, then its resistance will be:

R is directly proportional to length of the conductor.

A wire is 1.0 m long, 0.2 mm in diameter and has a resistance of 10 ohm. Calculate the resistivity of its material?

What will be the resistance of a metal wire of length 2 m and area of cross section 1.55 × 10^-6 m², if the resistivity of the metal be 2.8 × 10^-8 ohm m?

See the details in the given circuit, the current of 0.24A also flows through the 12 ohm resistor which is connected in series. Calculate the potential difference across 12 ohm resistor.

Find V1, V2 and V3 which are the p.ds across the 1ohm, 2ohm and 3 ohm resistors in the following diagram, and the current is 5A.

Details are given in the above circuit. Calculate the total resistance in the circuit.

The lamps in a household circuit are connected in parallel because:

Using the circuit given, state which of the following statement is correct?

Which of the following does not represent electrical power in a circuit?

How many joules are there in 1 kilowatt-hour

Which of the following is likely to be the correct wattage for an electric iron used in our homes?

The SI unit of energy is

An electric kettle for use on a 230 V supply is rated at 3000 W. For safe working, the cable connected to it should be able to carry atleast:

At a given time, a house iis supplied with 100 A at 220 V. How many 75 W, 220 V light bulbs could be switched on in the house at the same time (if they are connected in parallel)?

An electric heater is rated at 2 kW. Electrical energy costs Rs.4 per kW. What is the cost of using the heater 3 hours?

The heat produced by passing an electric current through a fixed resistor is proportional to the square of:

The heat produced in a wire of resistance 'x' and a current 'y' flows through it in time 'z' is given by:

An electric fuse works on the:

The elements of electrical heating devices are usually made of:

In a filament type light bulb, most of the electric power consumed appears as:

Which of the following is the most likely temperature of the filament of an electric light bulb when it is working on the normal 220 V supply line?

A p.d. of 250 volts is applied across a resistance of 500 ohm in an electric iron. Calculate the heat energy produced in joules in 10 seconds.

Calculate the heat produced when 96000 coulombs of charge is transferred in 1 hour through a potential difference of 50 volts

A battery of 10 volt carries 20,000 C of charge through a resistance of 20 Ω. The work done in 10 seconds is

See the diagram and find the resistance

Two resistors are connected in series gives an equivalent resistance of 10 Ω. When connected in parallel, gives 2.4 Ω. Then the individual resistance are

Two wires of same length and area made of two materials of resistivity ρ1 and ρ2 are connected in series to a source of potential V. The equivalent resistivity for the same area is

Two devices are connected between two points say A and B in parallel. The physical quantity that will remain the same between the two points is

Calculate the current flows through the 10 Ω resistor in the following circuit.

A fuse wire repeatedly gets burnt when used with a good heater. It is advised to use a fuse wire of

A cooler of 1500 W, 200 volt and a fan of 500 W, 200 volt are to be used from a household supply. The rating of fuse to be used is

A cell, a resistor, a key, and an ammeter are arranged as shown in the circuit diagrams. The current recorded in the ammeter will be

The slope of voltage (V) versus current (I) is called

Identify the correct circuit diagram:

In the experimental verification of Ohm’s law, the function of Rheostat is

What is the amount of current flowing through an electric press, if the amount of charge passing through a conductor in 10 minutes is 300 C?

Two electric bulbs have resistances in the ratio 1:2. If they are joined in series, the energy consumed in them is in the ratio.

Which of the following shows heating effect of electric current

The resistivity does not change if

The electrical resistance of insulators is

A student carries out an experiment and plots the V-I graph of three samples of nichrome wire with resistances R₁ R₂ and R₃ respectively. Which of the following is true?

Find the current drawn from the battery by the network of four resistors Shown in the figure.

The temperature of a conductor is increased. The graph best showing the variation of its resistance is

Calculate the resistance of an aluminium cable of length 10 km and diameter 2.0 mm if the resistivity of aluminium is 2.7 × 10^-8 ohm m.

A battery and three lamps are connected as shown:

Which of the following statements about the currents at X, Y and Z is correct?

Assertion (A) : Tungsten metal is used for making filaments of incandescent lamps.

Reason (R) : The melting point of tungsten is very low.

Assertion (A) : Longer wires have greater resistance and the smaller wires have lesser resistance.

Reason (R) : Resistance is inversely proportional to the length of the wire.

Assertion (A) : Alloys are commonly used in electrical heating devices, like electrical iron,

toasters etc.

Reason (R) : Alloys do not oxidise (burn) readily at high temperatures

Assertion (A) : When the resistances are connected between the same two points, they are said

to be connected in parallel.

Reason (R) : In case the total resistance is to be decreased, then the individual resistances are

connected in parallel.

Assertion (A) : The resistivity of a substance does not depend on the nature of the substance

and temperature.

Reason (R) : The resistivity of a substance is a characteristic property of the material.

Assertion (A) : The fuse is placed in series with the device.

Reason (R) : Fuse consists of a piece of wire made of a metal or an alloy of appropriate melting

point.

Assertion (A) : Electron has a negative charge.

Reason (R) : Electrons move always from a region of higher potential to a region of lower potential.

Assertion (A) : A voltmeter and ammeter can be used together to measure resistance but not power.

Reason (R) : Power is proportional to voltage and current.

2. When a glass rod is rubbed with skin cloth, then the charge produced on glass rod is --

The force between two like charges is --

1 coulomb charge contains the charge on --

The potential at a point is 20 V . The work done in bringing a charge of 0.25 C from infinity to this point will be -

S . I. Unit of potential difference is -

S . I. Unit of electric current is -

Joule / Coulomb is similar to the -

The device used to measure the potential diffrence is -

The resistance of voltmeter should be -

The device used to measure the electric current is -

In a metal -

Electric potential can be expressed as -

The number of free electrons constituting one coulomb of charge is -

The potential difference across a 4 $$\Omega$$  resistor is 8 V . The current flowing through the resistor will be :

The S. I. unit of electrical resistance is :

In ohm's law , the quality expressed by the reciprocal of the slope of V-I curve is :

A car headlight bulb works on a 12 V battery draws a current of 0.5 A ,the resistance of bulb is :

The best conductor is :

Ohm's law gives the relationship between :

The substance whose resistivity is infinity high is called :

With increase in temperature of a resistance wire , its resistance :

The resistivity of substance depends on the :

Keeping the potential difference constant the resistance of a circuit is halved . The current will become :

S. I. Unit of resistivity is :

When area of cross section of a conductor is doubled , its resistance becomes :

When area of cross section of a conductor is halved ,then its resistance becomes :

A wire is drawn such that its radius changes from r to 2r . The new resistance is :

Copper is a :

Nichrome is a :

Two wires 1 m and 2 m long respectively are taken , their area of cross sections are same . The resistance of :

Two wires of copper , one is 0.5 m long and other is 1 m long are taken . The resistivity of first wire will be :

What length of a wire (resistivity 48 x $$10^{-8}\Omega$$ m) is required to make a resistance of 4.2  $$\Omega$$  (radius = 0.2 mm ):

Ohm's law can be verified only if :

When two or more resistors are connected end to end consecutively , they are said to be conneted in :

When two or more resistor are connected between the same two points, they are said to be connected in :

Three resistors of resistance 2 $$\Omega$$  ,4  $$\Omega$$  ,6 $$\Omega$$  are joined in series , the equivalent resistance of combination will be : 

Two resistors of 6 $$\Omega$$  and 12 $$\Omega$$   are joined in parallel the equivalent resistance will be :

When the resistance of a circuit is to be increased , then which of the following combination of resistors should be used :

The equivalent resistance of the circuit given below is :

The lamps in a household circuit are connected in parallel because :