a conductor of length l is connected to a dc source of potential V. if the length of the conductoris tripled by stretching it keeping V constant explain how the following vary in the conductor driftspeed of the electrons, resistance and resistivity.

Draw a graph to show the variation of resistance of a metal wire as a function of its diameter ,keeping length and temperature constant.

how to find range ,of ammeter and voltmeter and resistance of wire using ohm's law? please answer fast .i have model tommorow!!!.

The temperature coefficient of resistance of a wire is 0.00125 per degree celsius . At 300 K temperature its resistance is 1 ohm. The resistance of the wire will be 2 ohm at:

1. (a) 1154 K
2. (b) 1100 K
3. (c) 1400 K
4. (d) 1127 K

I want a derivation on- Derive a relation containing drift velocity and electric current. Hence proove that the current density is directly proportional to relaxation time.

Two students X and Y performed an experiment on the potentiometer wire using the circuit.keeping other parameters unchanged how will the position of the null point hb affected if 1. X increases the value of Rby keeping key k1 closed and key k2 open

2.Y decreases the value of S in th e setup while the key k2 remains open and the keyk1 closed..??

if a copper wire is stretched to decrease the radius by 0.1 %, what is the percentage change in its resistance ?

when a galvanometer is shunted with a 4ohm resistance ,the deflection is reduced to one-fifth .If the galvanometer i further shunted with 2ohm wire,determine current in galvanometer now if initilly current in galvanometer is I'(given main current remains same)

A wire of uniform cross section area and length has a resistance of 16 ohm. It is cut into 4 equal parts and each part is stretched uniformly to length 'l' and all 4 parts are connected in parallel. Calculate the total resistance of combination so formed

The temperature coefficient of resistance of tungsten is 4.5 x 10^{-3 0}c^-1 and that of germanium is -5 x 10^{-2 0}c^-1 . A tungsten wire of resistance 100 ohms is connected in series with a germanium wire of resistance R. The value of R for which the resistance of combination does not change with temperature is:

a. 9 ohms

b. 1111 ohms

c. 0.9 ohms

d. 111.1 ohms

a galvanometer of resistance 100ohm gives full scale deflection at 10mA current . what should be the value of shunt so taht it can measure a current of 100mA

1) 11.11ohm

2) 1.1ohm

3) 9.9ohm

4) 4.4ohm

two cells of e.m.f E1 and E2 are joined in series and the balancing lenght of the potentiometer wire is 625cm. if the terminals of E1 are reversed , the balancing lenght obtained is 125cm . given E2 greater than E1 , the ratio E1:E2 will be

1) 2:3

2)5:1

3)3:2

4)1:5

the same mass of aluminium is drawn into two wires 1mm and 2mm thick. two wires are connected in series and current is passed through them. heat produced in the wire is in ratio

1) 16:1

2) 8:32

3) 8:2

4) 4:2

When two identical batteries of internal resistance 1 ohm each are connected in series across a resistor R, the rate of heat produced in R is P1. When the same batteries are connected in parallel across R the rate of heat produced is P2. If P1=2.25 P2, find the value of resistance R.

a cell sends a current through a resistance R for time t. Now the same cell sends current throughanother resistance r for the same time. If same amount of heat is developed in both the resistance, then the internal resistance of cell is

1) (R+r)/2

2) (R-r)/2

3)(Rr)/2

4) (Rr)^1/2

An electric kettle takes a 4A current at 220V . How much time will it take to boil 1kg of water from temperature 20degrees C? The temperature of boiling water is 100degrees C.

1- 4.2min 2- 6.3 min

3- 8.4 min 4- 12.6 min

The external diameter of of a 5m long hollow tube is 10cm and the thickness ofits wall is 5mm. If the specific resistance of copper 1.7 x 10^-5 ohm-meter, then determine its resistance.

A potentiometer wire of length l and resistance 10 ohm is connected in series with a battery of emf 3 V and a resistence R in the primary circuit of potentiometer. If a cell of emf 1 V get balanced against a length L/2 of the wire, then the value of R is :-

(a) 1 ohm

(b) 1.5 ohm

(c) 4 ohm

(d) 5 ohm

Plz. reply quickly- this is pending for more thantwo weeks

In a large building, there are 15 bulbs of 40W, 5 bulbs of 100W, 5 fans of 80W and 1 heater of 1kW. The voltage of electric mains is 220V. The minimum capacity of main fuse of the building will be-

1) 8A 2) 10A 3) 12A 4) 14A

A (100W,200V) bulb is connected to a 160 volt supply. The power consumption would be

1-100W 2- 125W

3-64W 4- 80W

A 6 volt battery is connected to the terminals of a 3 metre long wire of uniform thickness and resistance of 100 ohm. The difference of potential between 2 points seperated by a distance of 50cm will be?

1. 125 W
2. 80 W
3. 20 W
4. 5 W

A wire of resistance 18 ohm is bent to form an equilateral triangle . the resistance across any two vertices of the triangle is (in ohm)

A) 12 B) 6 C) 4 D) 9

A 4 microfarad capacitor is charged to 400V. If its plates are joined through a resistance of 2kohm, then heat produced in the resistance is?

1- 0.64J 2- 1.28J

3- 0.16J 4- 0.32J

if 2 bulbs rated 2.5 w-110v and 100w-110v are connected in series to a 220v supply then which bulb will fuse first?

please explain conceptually....

a 6V battery is connected to a terminals of a 3m long wire of uniform thickness and resistance of 100ohm along with another 100ohm resistor in series . the difference of potentials between two points on the wire separated by a distance of 50cm will be

1) 2V

2)3V

3)1V

4)0.5V

there are a large number of cells available , each marked (6V, 0.5ohm) to be used to supply current to a device of resistance 0.75ohm, requiring 24A current. how should the cells be arranged , so that power is transmitted to the load using minimum number of cells?

1) 6 rows, each containing 4cells

2) 4 rows, each containing 6 cells

1. 2E/n
2. 2E(1-1/n)
3. 4E/n
4. 2E(1-2/n)

If we double the number of turns in a moving coil galvanometer then its

A) current sensitivity doubles but voltage sensitivity remains unchanged

B) voltage sensitivity doubles but current sensitivity remain unchanged

C) both current and voltage sensitivity double

D) Both current and voltage sensitivity remain unchanged

a wire of reistance 0.1ohm/cm bent to form a squareABCD of side 10 cm .A similar wire is connected between the corners from B to D to form the diaonal BD.Find the effective resistance of this combination between corners A and C .If a 2V battery of negligible internal resistance is connected across A and C calculate the total power dissipated

1. R/2
2. R/16
3. 2R
4. 4R

What is ohm's law ?

An electron of mass m moves around the nucleus in a circular orbit of radius r under the action of centripetal force F.what is the equivalent electric current?

A and B are two points on a uniform ring of resistance R.The angle acb=thetawhere c is the centre of the ring .T...

Asked byKishan Shukla3 minutes agoSubject:Physics

a piece of wire is cut into four equal parts and the pieces are bundled together side by side to form a thicker wire. compared with that of the original wire , the resistance of bundle is

1) same

2) 1/16 as such

two cells of emf 10V and 15V are connected in parallel to each other between points A and B .the cell of emf 10V is ideal but the cell of emf 15 V has internal resistance 1ohm.The equivalenyt emf between A and B is

A 50 W bulb connected in series with a heater coil is put to an AC mains. Now the bulb is replaced by a 100W bulb. The heater output will

1. Double

2. Halve

3. Increase

4. Decrease