### Eamcet - Physics - Current Electricity Test

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The emf of a Cu-Fe thermocouple varies with the temperature T of the hot junction, the cold junction being at 100C, as Vinμv=14T-0.02T2.Determinate the neutral temperature and the of inversion.

Two cells A and B are connected in the secondary circuit of a potentiometer one at a time and the balancing length are respectively 400 cm and 440 cm. The emf of the cell A is 1.08 volt. The emf of the second cell B in volts is :

In a metre bridge experiment, the ratio of the left gap resistance to right gap resistance is 2 : 3, the balance point from left is

Temperature of cold junction in a thermo- couple is 100C and neutral temperature is 2700C, then the temperature of inversion is

In a meterbridge experiment,the balance length is 40cm.the resistance in the gap opposite to this length of wire is 8 ohm.The resistance in the other gap is

The lengths of two wires made of same material are 2m and 1m. Their radii are 1mm and 2mm. The ratio of their specific resistances is

The resistance of a conductor is 1.08Ω.To reduce it to 1Ω,the resistance that must be connected is

In a potentiometer experiment, when a resistance of 10 ohm is connected in parallel to the cell in secondary circuit , the balancing length is 350 cm. when 10 ohm resistance is replaced by 20 ohm resistance, the balancing length becomes 420 cm.The internal resistance of the cell in secondary circuit is

Thermo emf produce per 10C temperature difference between the junction is 0.005V.when cold junction is at 100C,and hot junction is at t0C,thermo emf produced is 0.5 V.,The value of t is

When an unknown resistance and a resistance of 4Ω are connected in the left and right gaps of a meterbridge, the balance point is obtained at 50cm. The shift in the balance point if a 4Ω resistance is now connected in parallel to the resistance in the right gap is

When an unknown resistance of 4Ω are connected in the left and right gaps of a meterbridge,the balance point is obtained at 50cm.The shift in the balance point if a 4 Ω resistance is now connected in parallel to the right gap is

One end each of a resistance r capacitor C and resistance 2r are connected together. The other ends are respectively connected to the positive terminals of batteries, P, Q, R having respectively emfs E, E and 2E. The negative terminals of the batteries are then connected together. In this circuit, with steady current the potential drop across the capacitor is ;

In a meter bridge a 30 Ω resistance is connected in the left gap and a pair of resistances P and Q in the right gap. Measured from the left, the balance point is 37.5 cm, when P and Q are in series and 71.4 cm when they are parallel. The values of P and Q (in Ω ) are

A galvanometer of resistance 100Ω gives full scale deflection with 5mA current.To convert it into a 5 volt range voltmeter,the value of resistance connected in series is

The cold junction of a thermocouple is at 00 C,The thermo e.m.f produced in the thermocouple is given by the equation E=16T-0.04T2V , where T is the temperature of the hot junction.The temperature of inversion and neutral temperature of the thermo couple are

Thomson coefficient of a conductor is 10μV/K.The two ends of it are kept at 500C and 600C respectively.Amount of heat absorbed by the conductor when a charge of 10C flows through it is

A potentiometer wire of length 100 cm has a resistance of 10 Ω. It is connected in series with a resistance and a cell of emf 2V and of negligible internal resistance. A source of emf 10 mV is balanced against a length of 40 cm of the potentiometer wire. The value of external resistance is:

A cell of emf 2V and negligible resistance is connected in series with a resistance of 5 ohm,and a potentiometer wire of resistance 10 ohm.what is the potential drop per cm if the length of the potentiometer wire is 10m.The emf of a cell which is balanced by 750cm long wire is

The equation connecting thermo emf with the temperature difference between the junctions 't' of a thermocouple, whose cold junction is maintained at 00C, is given by e = 2040 t - 6.2 t2. The neutral and inversion temperatures of the thermocouple in C .ire respectively and nearly equal to:

If π is Peltier coefficient,heat evolved at a junction when a current of 10 mA passes for 10 seconds in joules is

When two unknown resistances are placed in the gaps of meterbridge,the null point is found to be 40cm from one end of the bridge wire.when one of the resistances is shunted with a 10 ohm coil,the null points is 25cm form the same end.The value of each of the unknown resistances is

There are 5 tube-lights each of 40W in a house.These are used on an average for 5 hours per day.In addition ,there is an immersion heater of 1500W used on an average for 1 hour per day.The number of units of electricity are consumed in a month is

In a potentiometer using two cells in series gave a balance length 600cm. When the same cells are connected opposing each other then balance length is 100cm. The ratio of emf’s of the cells is

Four bulbs each marked 40 W. 250 V are connected in series with 250 V source. The total power output is

Two wires of the same material but of different diameters carry the same current I. If the ratio of their diameters is 2 : 1, then the corresponding ratio of their mean drift velocities will be

A cell of emf 2V and negligible resistance is connected in series with a resistance of 5 Ω, and a potentiometer wire of resistance 10 ohm. What is the potential drop per cm if the length of the potentiometer wire is 10 m. The emf a cell which is balanced by 750 cm long wire is

A cell of emf e1 in the secondary circuit gives null deflection for1.5m length of potentiometer of wire length 10m.If another cell of emf e2 is connected in series with e1 then null reflection was obtained for 2.5 m length.Then e1:e2

While connecting 6 cells in a battery in series,ina tape recorder,by mistake one cell is connected with reverse polarity.If the effective resistance of load is 24 ohm and internal resistance of each cell is one ohm and emf 1.5V,the current delivered by the battery is

In Potentiometer experiment,the balancing length with a cell in the secondary circuit is found to be 480cm.when a resistor of 8 ohm is connected in parallel to the cell the balancing length is found to be 420cm.The internal resistance of the cell is

In a thermo couple the temperature of the cold junction is 150C.If the temperature of inversion is 4850C,the neutral temperature of the thermo couple is

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