Physics M.C.Q (1 Marks)

The V-i graph for a conductor makes an angle θ with V-axis. Here V denotes the voltage and i denotes current. The resistance of conductor is given by

Assertion : A person touching a high power line gets stuck with the line.
Reason : The current carrying wires attract the man towards it.

Assertion : A potentiometer of longer length is used for accurate measurement.
Reason : The potential gradient for a potentiometer of longer length with a given source of e.m.f. becomes small.

Assertion : The resistance of super-conductor is zero.
Reason : The super-conductors are used for the transmission of electric power.

Assertion : Electric field outside the conducting wire which carries a constant current is zero.
Reason : Net charge on conducting wire is zero.

Assertion : In meter bridge experiment, a high resistance is always connected in series with a galvanometer.
Reason : As resistance increases current through the circuit increases.

Assertion : Bending a wire does not effect electrical resistance.
Reason : Resistance of wire is proportional to resistivity of material.

Assertion : The electric bulbs glows immediately when switch is on.
Reason : The drift velocity of electrons in a metallic wire is very high.

Assertion : The drift velocity of electrons in a metallic wire will decrease, if the temperature of the wire is increased.
Reason : On increasing temperature, conductivity of metallic wire decreases.

Assertion : Electric appliances with metallic body have three connections, whereas an electric bulb has a two pin connection.
Reason : Three pin connections reduce heating of connecting wires.

Assertion : In a simple battery circuit the point of lowest potential is positive terminal of the battery
Reason : The current flows towards the point of the higher potential as it flows in such a circuit from the negative to the positive terminal.

Assertion : The temperature coefficient of resistance is positive for metals and negative for p-type semiconductor.
Reason : The effective charge carriers in metals are negatively charged whereas in p-type semiconductor they are positively charged.

Assertion : There is no current in the metals in the absence of electric field.
Reason : Motion of free electron are randomly.

In an experiment, a graph was plotted of the potential difference V between the terminals of a cell against the circuit current i by varying load rheostat. Internal conductance of the cell is given by

A battery consists of a variable number 'n' of identical cells having internal resistances connected in series. The terminals of battery are short circuited and the current i is measured. Which of the graph below shows the relation ship between i and n

A wire of resistor R is bent into a circular ring of radius r. Equivalent resistance between two points X and Y on its circumference, when angle XOY is a, can be given by

A cylindrical conductor has uniform cross-section. Resistivity of its material increase linearly from left end to right end. If a constant current is flowing through it and at a section distance x from left end, magnitude of electric field intensity is E, which of the following graphs is correct

When a current I is passed through a wire of constant resistance, it produces a potential difference V across its ends. The graph drawn between log I and log V will be

The graph which represents the relation between the total resistance R of a multi range moving coil voltmeter and its full scale deflection V is

For a cell, the graph between the potential difference (V) across the terminals of the cell and the current (I) drawn from the cell is shown in the figure. The e.m.f. and the internal resistance of the cell are

Which of the adjoining graphs represents ohmic resistance

Variation of current passing through a conductor as the voltage applied across its ends as varied is shown in the adjoining diagram. If the resistance (R) is determined at the points A, B, C and D, we will find that

From the graph between current I and voltage V shown below, identify the portion corresponding to negative resistance

I-V characteristic of a copper wire of length L and area of cross-section A is shown in figure. The slope of the curve becomes

The two ends of a uniform conductor are joined to a cell of e.m.f. E and some internal resistance. Starting from the midpoint P of the conductor, we move in the direction of current and return to P. The potential V at every point on the path is plotted against the distance covered (x). Which of the following graphs best represents the resulting curve
 

Variation of current and voltage in a conductor has been shown in the diagram below. The resistance of the conductor is

A moving coil galvanometer has 150 equal divisions. Its current sensitivity is 10 divisions per milliampere and voltage sensitivity is 2 divisions per millivolt. In order that each division reads 1 volt, the resistance in ohms needed to be connected in series with the coil will be

The resistance of the series combination of two resistance is S. When they are joined in parallel the total resistance is P. If S = nP, then the minimum possible value of n is

The reading of the ideal voltmeter in the adjoining diagram will be

In the adjoining circuit diagram each resistance is of 10 W. The current in the arm AD will be

Following figure shows cross-sections through three long conductors of the same length and material, with square cross-section of edge lengths as shown. Conductor B will fit snugly within conductor A, and conductor C will fit snugly within conductor B. Relationship between their end to end resistance is

12 cells each having same emf are connected in series with some cells wrongly connected. The arrangement is connected in series with an ammeter and two cells which are in series. Current is 3 A when cells and battery aid each other and is 2 A when cells and battery oppose each other. The number of cells wrongly connected is

V-i graphs for parallel and series combination of two identical resistors are as shown in figure. Which graph represents parallel combination

In order to quadruple the resistance of a uniform wire, a part of its length was uniformly stretched till the final length of the entire wire was 1.5 times the original length, the part of the wire was fraction equal to

In the following circuit, bulb rated as 1.5 V, 0.45 W. If bulbs glows with full intensity then what will be the equivalent resistance between X and Y

Potential difference across the terminals of the battery shown in figure is (r = internal resistance of battery)

In the circuit shown here, the readings of the ammeter and voltmeter are

A battery of internal resistance 4W is connected to the network of resistances as shown. In order to give the maximum power to the network, the value of R (in Ω) should be

Seven resistances are connected as shown in the figure. The equivalent resistance between A and B is

In the shown arrangement of the experiment of the meter bridge if AC corresponding to null deflection of galvanometer is x, what would be its value if the radius of the wire AB is doubled