AIPMT-PRELIMS Physics Current Electricity Class 12 Questions

A ring is made of a wire having a resistance R₀ = 12 Ω. Find the points A and B, as shown in the figure, at which a current carrying conductor should be connected so that the resistance R of the sub circuit between these points is equal to 8/3 Ω.

In the circuit shown the cells A and B have negligible resistances. For Vₐ = 12V, R₁ = 500 Ω and R = 100 Ω the galvanometer (G) shows no deflection. The value of V_b is

If voltage across a bulb rated 220 Volt^{-100} Watt drops by 2.5% of its rated value, the percentage of the rated value by which the power would decrease is

A milli voltmeter of 25 milli volt range is to be converted into an ammeter of 25 ampere range. The value (in Ω) of necessary shunt will be

If power dissipated in the 9 Ω resistor in the circuit shown is 36 Watt, the potential difference across the 2 Ω resistor is

A current of 2 Å flows through a 2 Ω resistor when connected across a battery. The same battery supplies a current of 0.5 Å when connected across a 9 Ω resistor. The internal resistance of the battery is

A potentiometer circuit is set up as shown. The potential gradient, across the potentiometer wire, is k volt/cm and the ammeter, present in the circuit, reads 1.0 Å when two way key is switched off. The balance points, when the key between the terminals (i) 1 and 2 (ii) 1 and 3, is plugged in, are found to be at lengths l₁ cm and l₂ cm respectively. The magnitudes, of the resistors R and X, in Ω, are then, equal, respectively, to

A galvanometer has a resistance of 100 Ω and gives a full scale deflection for 30 mA current. If it is to work as a voltmeter of 30 volt range, the resistance required to be added will be

Consider the following two statements (A) Kirchhoff's junction law follows from the conservation of charge. (B) Kirchhoff's loop law follows from the conservation of energy. Which of the following is correct?

See the electric circuit shown in this Figure. Which of the following equations is a correct equation for it?

A wire of resistance 12 Ω per meter is bent to form a complete circle of radius 10 cm. The resistance between its two diametrically opposite points, A and B as shown in the Figure, is:

A galvanometer having a coil resistance of 60 Ω shows full scale deflection when a current of 1.0 amp passes through it. It can be converted into an ammeter to read currents up to 5.0 amp by:

A student measures the terminal potential difference (V) of a cell (of emf ε and internal resistance r) as a function of the current (I) flowing through it. The slope, and intercept, of the graph between V and I, then, respectively, equal:

The mean free path of electrons in a metal is 4 × 10⁻⁸ m. The electric field which can give on an average 2 eV energy to an electron in the metal will be in units of V/m:

In the phenomenon of electric discharge through gases at low pressure, the coloured glow in the tube appears as a result of -

In the circuit shown, the current through the 4Ω resistor is 1 amp when the points P and M are connected to a D.C. voltage source. The potential difference between the points M and N is -

A wire of a certain material is stretched slowly by ten percent. Its new resistance and specific resistance become respectively -

A galvanometer of resistance 50 Ω is connected to a battery of 3V along with a resistance of 2950 Ω in series. A full scale deflection of 30 divisions is obtained in the galvanometer. In order to reduce this deflection to 20 divisions, the resistance in series should be -

A current of 3 amp. flows through the 2Ω resistor shown in the circuit. The power dissipated in the 5Ω resistor is -

A cell can be balanced against 110 cm and 100 cm of potentiometer wire, respectively with and without being short circuited through a resistance of 10 Ω. Its internal resistance is -

The total power dissipated in watts in the circuit shown here is

Three resistances P, Q, R each of 2Ω and an unknown resistance S form the four arms of a Wheatstone bridge circuit. When a resistance of 6Ω is connected in parallel to S the bridge gets balanced. What is the value of S?

Dimensions of resistance in an electrical circuit, in terms of dimension of mass M, of length L, of time T and of current I, would be

The resistance of an ammeter is 13 Ω and its scale is graduated for a current upto 100 amps. After an additional shunt has been connected to this ammeter it becomes possible to measure currents upto 750 amperes by this meter. The value of shunt-resistance is

In producing chlorine through electrolysis 100 W power at 125 V is being consumed. How much chlorine per min is liberated? ECE of chlorine is 0.367 × 10⁻⁶ kg/C:

In the circuit shown, if a conducting wire is connected between points A and B, the current in this wire will:

Two cells, having the same emf, are connected in series through an external resistance R. Cells have internal resistances r1 and r2 (r1 > r2) respectively. When the circuit is closed, the potential difference across the first cell is zero. The value of R is:

Power dissipated across the 8 Ω resistor in the circuit shown here is 2 W. The power dissipated in watt units across the 3 Ω resistor is:

Kirchhoff's first and second laws for electrical circuits are consequences of:

Two batteries, one of emf 18 V and internal resistance 2 Ω and the other of emf 12 V and internal resistance 1 Ω, are connected as shown. The voltmeter V will record a reading of:

For the network shown in the figure, the value of the current i is:

When a wire of uniform cross-section a, length l and resistance R is bent into a complete circle, resistance between two of diametrically opposite points will be:

A⁵⁻A fuse wire can withstand a maximum power of 1 W in circuit. The resistance of the fuse wire is:

When three identical bulbs of 60 watt, 200 volt rating are connected in series to a 200 volt supply, the power drawn by them will be :-

The electric resistance of a certain wire of iron is R. If its length and radius are both doubled, then:-

Resistances n, each of r Ω, when connected in parallel give an equivalent resistance of R Ω. If these resistances were connected in series, the combination would have a resistance in Ω, equal to

A galvanometer acting as a voltmeter will have :-

In India electricity is supplied for domestic use at 220 V. It is supplied at 110 V in USA. If the resistance of a 60W bulb for use in India is R, The resistance of a 60W bulb for use in USA will be :-

Five equal resistances each of resistance R are connected as shown in the Figure. A battery of V volts is connected between A and B. The current flowing in AFCB will be

A galvanometer of 50 Ω resistance has 25 divisions. A current of 4 × 10⁻⁴ ampere gives a deflection of one division. To convert this galvanometer into a voltmeter having a range of 25 volts, it should be connected with a resistance of :-

A 6 volt battery is connected to the terminals of a three metre long wire of uniform thickness and resistance of 100 Ω. The difference of potential between two points on the wire separated by a distance of 50 cm will be :-

Two 220 volt, 100 watt bulbs are connected first in series and then in parallel. Each time the combination is connected to a 220 volt a.c. supply line. The power drawn by the combination in each case respectively will be -

An electric kettle has two heating coils. When one of the coils is connected to an a.c. source, the water in the kettle boils in 10 minutes. When the other coil is used the water boils in 40 minutes. If both the coils are connected in parallel, the time taken by the same quantity of water to boil will be :

In a Wheatstone's bridge all the four arms have equal resistance R. If the resistance of the galvanometer arm is also R, the equivalent resistance of the combination as seen by the battery is :

Fuse wire is a wire of

Specific resistance of a conductor increases with :

For a cell terminal P.D. is 2.2V when circuit is open and reduces to 1.8V when cell is connected to a resistance of R = 5Ω. Determine internal resistance of cell (r) is then :-

The current (I) in the circuit will be:

Tangent galvanometer is used to measure :-

If specific resistance of a potentiometer wire is 10⁻⁷Ωm and current flow through it is 0.1 Å, cross-sectional area of wire is 10⁻⁶ m² then potential gradient will be :-