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Syllabus

State the principal and working of a meter bridge?

On what factors the internal resistence of a cell depends ?

$1.10\Omega 2.5\Omega 3.40\Omega 4.15\Omega $

Draw an equipotential surface due to an electric dipole.

Emf of a cell is 1.5V and its internal resistance is 1ohm.For what current drawn from the cell will the terminal potential difference be half of its emf?

why are alloys manganin constantan used to make standard resistance coil?

derive relation between current density and potential difference across a current carrying conductor of length l,area of cross section A and number density of free electron n

project onto study various factors on which the internal resistance/emf of a cell depends.

Define 1 Ampere.

please answer all of them. they are from meter bridge experiment class 12

2. If the metre bridge wire is not of uniform area of cross section,

how will it affect the observations?

Fig. E 2.3 Defective scale of a metre bridge

3. If the metre bridge wire is not made of a material of uniform density,

how will it affect the observations?

4. If the same experiment is performed with AC = 50 cm wire instead

of 1 m, what changes would be there in the result?

5. The scale attached along the wire may not indicate the exact

length as shown in Fig. E 2.3. How would you minimise the error?

6. Why is the metre bridge not suitable for measuring very

high/very low resistances?

7. Why is the metre bridge preferred for determining the resistanceof a wire over the Ohms law circuit

derivation for ampere circuital law?

How to solve an unbalanced Wheatstone bridge?

the resistance of a silver wire at 0 degree celsius is 1.25 ohm.upto wat temp. it must b heated so dat its resistance is doubled?(alpha silver=0.00375/degree celsius.will d temp. be same for all silver conductors of all shapes??

how can sensitivity of potentiometer be increased

current density and number of free electrons per unit volume

answer-

current density=2.4*1)^5A/m square

n=8.8*10^28

What is the dimensional formula of potential difference

What is the definition of meter bridge?

No links plzz...

The network PQRS shown in the circuit diagram has the battery of 4V and 5V and negligible internal resistance. A milliammeter of $20\Omega $ resistance is connected between P and R. Calculate the reading in the ammeter.

What are the conditions for total internal reflection?

_{2}He^{4}) is revolving in a circular orbit of radius 3.14A with speed of 8*10^{6}m/s .then the equivalent current is ?the emf of a cell is always greater than its terminal voltage.why?give reason.

thet 3 identical resistors R1,R2 and R3 are connected to a battery as shown in the fig. what wil b d ratio of voltages across R1 andR2?

why is potentiometer preferred over voltmeter?

Q. For the circuit shown calculate the potential difference between point B and D.

what is the dimension of resistance....????

a copper wire is streched to make it 0.1%lonnger.what is the percentage change in resistance?

Three cells of emf 2V,1.8V and 1.5V are connected in series.Their internal resistances are 0.05ohm, 0.7ohm and 1ohm respectively.If the battery is connected to an external resistor of 4ohm via a very low resistance of ammeter, what would be the reading in the ammeter?

what is vacus junction?

A balloon starts rising from ground rest with an upward acceleration 2 m/secsqu. just after 1 sec. a stone is dropped from it the time taken by stone to strike the ground is nearly?

10^9 electrons pass from A to B in 10^-3 second.Calculate the strength of current and give its direction.

ans is 1.6*10^-7A.

the resistance of the platinum wire of a platinum resistance thermometer at the ice point is 5 ohm and at steam point is 5.23 ohm .When the thermometer is inserted in a hot bath , the resistance of the platinum wire is 5.795 ohmcalculate the temprature of the bath

what are the advantages of potentiometer over votlmeter ?

In example no 3.6 at page 116 of NCERT Physics, the value of R is found to b 5/6 ohm.. bt i think that it's incorrect.. it shud b 5/4 ohm...

Even if v put the valur of R=5/6 ohm in the formula I=V/R then v dnt get the current I as 4 A.. But on putting R=5/4 ohm, v get the correct value of I too. So it shud b 5/4 and not 5/6....

Isnt it.....????????

show that electric field is conservative?

a carbon resistor of 74k ohm is to be marked with rings of different colours for its identification write the sequence of colours ?

the reading on a high resistance voltmeter when a cell is connected across it is 2.2 v . When the terminal of the cells are also connected to a resistance of 5 v ,the voltmeter reading drops to 6.8 v . Find the internal resistance of the cell?????1)60 W bulb will fuse. 2)100 W bulb will fuse 3)both bulbs will fuse.

4)Bulbs will not fuse

In a galvanometer there is deflection of 10 divisions per mA.Thje internal resistance of the galvanometer is 60 ohm.If a shunt of 2.5 ohm is connected to the galvanometer and there are 50 divisions in all,on the scale of galvanometer,what maximum current can this galvanometer read?

MY DOUBT IS:(If wrong plz correct it and explain) Since there are 50 divisions in all in the galvanometer,then maximum current that galvanometer would read is I_{g}=50*1/10=5 mA .But the answer is given 125 mA.How?1. 1A, 0A, 1A

2. 2A, 1A, 1A

3. 1A, 0.5A, 0.5A

4. None of these

how does drift velocity of electron in a metallic conductor vary with temperature?

A steady current flows in a metallic conductor of non-uniform cross section.Which of these quantities is constant along the conductor-

1)Current

2)Current density

3)Drift speed

4)Electric field

voltmeters v1 and v2 are connected in series across a dc line.v1 reads 80 volt and has a per volt resistance of 200 ohm.v2 has a total resistance of 32kohm.what is the line voltage??

A resistance or R ohm draws a current from a potentiometer.The potentiometer has a total resistance R

_{0}ohm.A voltage V is supplied to the potentiometer .Derive an expression for the voltage fed to the ckt when the slide is in the middle of the potentiometer.How is I=Qv and I=QA please explain. these formulae have been used in my guide.

A wire of resistance 8R is bent in the form of a circle. What is the effective resistance between the ends of a diameter AB?

Explain the variation of conductivity nwith temp for (a) A metallic conductor (b) ionic conductor

four cells in a battery , each of internal resistance 0.8 ohm and emf 1.4V are connected (a) in series , (b) in parallel . the terminals of the battery are joined to to a lamp of resistance 10 ohm. find the current through thelamp and the cell in each case.

Two conducting wires X and Y of same diameter but different material are joined in series across the battery. If the number density of electron in X is twice that in Y, fined ratio of drift velocity of electron in two wires

a uniform wire of resistance 36 ohm is bent in tne form of a circle .calculate the effective resistance across the points A and B.

is current is scalar or vector quantity?

please explain stepwise with formulae....

The supply voltage to a room is 120V.The resistance of lead wires is 6 ohm.A 60 W bulb is already switched on.What is the decrease of voltage across the bulb when a 240 W heater is switched on in parallel with the bulb?

a)0 V b)2.9 V c)13.3 V d) 10.04 V

Using Kirchhoff’s Law determine the current I1, I2 and I3 for the network shown below:

Q. Find the current through the battery as a function of time. Initially the switch K is open at S is closed at timet =3 RC, switch 'S' is opened and switch K is closed. Calculate the heat dissipated in the resistors after very long time.Q.10. A wire connected to a cell of constant emf. If the wire is stretched to increase it's length by 200 %. Calculate change in it's resistivity and resistance, drift speed and current density.

My Question:

Draw V-I Graph for both ohmic and non-ohmic materials stating one example of each as well.thanks!

a wire of 15 ohm resistance is gradually stretched to double its original length. it is then cut into two equal parts. these parts are connected in parallel across a 3 V cell. find the current drawn from the cell

A storage battery of emf 8V and internal resistance 0.5 ohm is being charged by a 120 V d.c supply using a series resistor of 15.5 ohm. What is the terminal voltage of the battery during charging? what is the purpose of having a series resistor in the charging ciruit?

12 identical resistance R each form a cube . Resistance across its face diagonal corners is?

Draw the circuit diagram and using Kirchhorf's laws, calculate the current through each branch of the circuit and potential difference across the 5 ohm resistor.

19. The equivalent capacitance of the circuit as shown in figure between points A and B is

(1) 10 µF

(2) 8 µF

(3) 2 µF

(4) 15 µF

derive the expression for drift velocity in an electric field.

what are kirchhoff's law?explain them.

give two possible causes for one sided deflection in a potentiometer experiment.

why is a copper wire used in a sonometer to find the frequency of A.C mains?plz i hv my board practicals 2morow.friends and xperts plz help

1 NEWTON =how many dyne?

why do we perfer a 10 wire potentiometer to 4 wire potentiometer ?

A cylindrical metallic wire is stretched to increase its length by 5%. Calculate the percentage change in its resistance.

A 200-V bulb takes a current of 0.2 A. The length of its filament is 22 cm and the specific resistance of the material of the filament is 7 * 10^-5 ohm-cm. Find the radius of the filament. (pi=22/7)

what is the main difference between DC n AC current???

ans is 6*10^-4, 3.75*10^15