A wheat stone bridge is used to determine the value of unknown resistance X by adjusting the variable resistance Y as shown in the figure. For the most precise measurement of X , the resistances P and Q :


(1). Should be approximately equal to 2X
(2). Should be approximately equal and are small
(3). Should be very large and unequal
(4). Do not play any significant role

Number of Attempts: 2

Correct Attempts: 1

Time Taken: 00:04

Average Time: 00:02

Column-I gives certain physical terms associated with flow of current through a metallic conductor. Column-II gives some mathematical relations involving electrical quantities.
Match Column-I and Column-II with appropriate relations.


(1). (A) - (R), (B) - (S), (C) - (P), (D) - (Q)
(2). (A) - (R), (B) - (S), (C) - (Q), (D) - (P)
(3). (A) - (R), (B) - (P), (C) - (S), (D) - (Q)
(4). (A) - (R), (B) - (Q), (C) - (S), (D) - (P)

Number of Attempts: 2

Correct Attempts: 1

Time Taken: 00:04

Average Time: 00:02

In the circuits shown below, the readings of the voltmeters and the ammeters will be

(1). V 2 > V 1 and i1 > i2
(2). V 2 > V 1 and i1 = i2
(3). V 1 = V 2 and i1 > i2
(4). V 1 = V 2 and i1 = i2

Number of Attempts: 2

Correct Attempts: 1

Time Taken: 00:04

Average Time: 00:02

Which of the following acts as a circuit protection device?

(1). fuse
(2). conductor
(3). inductor
(4). switch

Number of Attempts: 2

Correct Attempts: 1

Time Taken: 00:04

Average Time: 00:02

A potentiometer wire is 100 cm long and a constant potential difference is maintained across it. Two cells are connected in series first to support one another and then in opposite direction. The balance points are obtained at 50 cm and 10 cm from the positive end of the wire in the two cases. The ratio of emf's is

(1). 3 : 4
(2). 3 : 2
(3). 5 : 1
(4). 5 : 4

Number of Attempts: 2

Correct Attempts: 1

Time Taken: 00:04

Average Time: 00:02

The current passing through the battery in the given circuit is:


(1). 1.5 A
(2). 2.0 A
(3). 0.5 A
(4). 2.5 A

Number of Attempts: 2

Correct Attempts: 1

Time Taken: 00:04

Average Time: 00:02

A constant voltage of 50 V is maintained between the points A and B of the circuit shown in the figure. The current through the branch CD of the circuit is:


(1). 3.0 A
(2). 1.5 A
(3). 2.0 A
(4). 2.5 A

Number of Attempts: 2

Correct Attempts: 1

Time Taken: 00:04

Average Time: 00:02

A wire of resistance R is cut into 8 equal pieces. From these pieces two equivalent resistances are made by adding four of these together in parallel. Then these two sets are added in series, The net effective resistance of combination is:

(1). \(\displaystyle \frac{R}{8}\)
(2). \(\displaystyle \frac{R}{64}\)
(3). \(\displaystyle \frac{R}{32}\)
(4). \(\displaystyle \frac{R}{16}\)

Number of Attempts: 2

Correct Attempts: 1

Time Taken: 00:04

Average Time: 00:02

AB is a part of an electrical circuit (see figure). The potential difference \(\text{"V}_\text{A}\,-\,\text{V}_\text{B}\text{"}\), at the instant when current \(i\,=\, 2\text{A}\) and is increasing at a rate of 1 amp/second is:


(1). 10 volt
(2). 5 volt
(3). 6 volt
(4). 9 volt

Number of Attempts: 2

Correct Attempts: 1

Time Taken: 00:04

Average Time: 00:02

The terminal voltage of the battery, whose emf is 10V and internal resistance 1Ω , when connected through an external resistance of 4Ω asshown in the figure is:


(1). 4V
(2). 6V
(3). 8V
(4). 10V

Number of Attempts: 2

Correct Attempts: 1

Time Taken: 00:04

Average Time: 00:02

A wire of length 'l' and resistance 100Ω is divided into 10 equal parts. The first 5 parts are connected in series while the next 5 parts are connected in parallel. The two combinations are again connected in series. The resistance of this final combination is:

(1). 26Ω
(2). 52Ω
(3). 55Ω
(4). 60Ω

Number of Attempts: 2

Correct Attempts: 1

Time Taken: 00:04

Average Time: 00:02

Two heaters A and B have power rating of 1 kW and 2 kW, respectively. Those two are first connected in series and then in parallel to a fixed power source. The ratio of power outputs for these two cases is:

(1). 1 : 1
(2). 2 : 9
(3). 1 : 2
(4). 2 : 3

Number of Attempts: 2

Correct Attempts: 1

Time Taken: 00:04

Average Time: 00:02

Choose the correct circuit which can achieve the bridge balance.

(1).
(2).
(3).
(4).

Number of Attempts: 2

Correct Attempts: 1

Time Taken: 00:04

Average Time: 00:02

Resistance of a carbon resistor determined from colour codes is (22000±5%) Ω. The colour of third band must be

(1). Green
(2). Orange
(3). Yellow
(4). Red

Number of Attempts: 2

Correct Attempts: 1

Time Taken: 00:04

Average Time: 00:02

The magnitude and direction of the current in the following circuit is


(1). 0.5A from A to B through E
(2). 5/9 A from A to B through E
(3). 1.5A from B to A through E
(4). 0.2A from B to A through E

Number of Attempts: 2

Correct Attempts: 1

Time Taken: 00:04

Average Time: 00:02

10 resistors, each of resistance R are connected in series to a battery of emf E and negligible internal resistance. Then those are connected in parallel to the same battery, the current is increased n times. The value of n is

(1). 100
(2). 1
(3). 1000
(4). 10

Number of Attempts: 2

Correct Attempts: 1

Time Taken: 00:04

Average Time: 00:02

The resistance of platinum wire at \(0^\circ C\) is \(2 \Omega\) and \(6.8 \Omega\) at \(80^ \circ C\). The temperature coefficient of resistance of the wire is

(1). \(3 \times 10^{−3\,\,^\circ} C^{−1} \)
(2). \(3 \times 10^{−2\,\, \circ} C^{−1}\)
(3). \(3 \times 10^{−1}C^{−1} \)
(4). \(3 \times 10^{−4\,\, \circ}C^{−1} \)

Number of Attempts: 2

Correct Attempts: 1

Time Taken: 00:04

Average Time: 00:02

As the temperature increases, the electrical resistance

(1). Increases for both conductors and semiconductors
(2). Decreases for both conductors and semiconductors
(3). Increases for conductors but decreases for semiconductors
(4). Decreases for conductors but increases for semiconductors

Number of Attempts: 2

Correct Attempts: 1

Time Taken: 00:04

Average Time: 00:02

Two resistors of resistance, 100 Ω and 200 Ω are connected in parallel in an electrical circuit. The ratio of the thermal energy developed in 100 Ω to that in 200 Ω in a given time is

(1). 1 : 2
(2). 2 : 1
(3). 1 : 4
(4). 4 : 1

Number of Attempts: 2

Correct Attempts: 1

Time Taken: 00:04

Average Time: 00:02

A copper wire of length 10 m and radius \(\displaystyle \left(\frac{10{^{−2}}}{\sqrt{\pi}}\right)\) m has electrical resistance of 10 Ω. The current density in the wire for an electric field strength of 10 (V ∕ m) is

(1). \(10^4\,A ∕ m^2\)
(2). \(10^6\,A ∕ m^2\)
(3). \(10^{−5}\,A ∕ m^2\)
(4). \(10^5\,A ∕ m^2\)

Number of Attempts: 2

Correct Attempts: 1

Time Taken: 00:04

Average Time: 00:02

The effective resistance of a parallel connection that consists of four wires of equal length, equal area of cross-section and same material is 0.25 Ω . What will be the effective resistance if they are connected in series?

(1). 0.25 Ω
(2). 0.5 Ω
(3). 1 Ω
(4). 4 Ω

Number of Attempts: 2

Correct Attempts: 1

Time Taken: 00:04

Average Time: 00:02

In a potentiometer circuit a cell of EMF 1.5 V gives balance point at 36 cm length of wire. If another cell of EMF 2.5 V replaces the first cell, then at what length of the wire, the balance point occurs?

(1). 60 cm
(2). 21.6 cm
(3). 64 cm
(4). 62 cm

Number of Attempts: 2

Correct Attempts: 1

Time Taken: 00:04

Average Time: 00:02

Three resistors having resistances r1, r2 and r3 are connected as shownin the given circuit. The ratio \(\displaystyle \frac{i_3}{i_1}\)of currents in terms of resistances usedin the circuit is

(1). \(\displaystyle \frac{r_1}{r_2 + r_3}\)
(2). \(\displaystyle \frac{r_2}{r_2 + r_3}\)
(3). \(\displaystyle \frac{r_1}{r_1 + r_2}\)
(4). \(\displaystyle \frac{r_2}{r_1 + r_3}\)

Number of Attempts: 2

Correct Attempts: 1

Time Taken: 00:04

Average Time: 00:02

Which of the following graph represents the variation of resistivity (\(\rho\)) with temperature (T) for copper?

(1).
(2).
(3).
(4).

Number of Attempts: 2

Correct Attempts: 1

Time Taken: 00:04

Average Time: 00:02

The solids which have the negative temperature coefficient of resistanceare:

(1). insulators only
(2). semiconductors only
(3). insulators and semiconductors
(4). metals

Number of Attempts: 2

Correct Attempts: 1

Time Taken: 00:04

Average Time: 00:02

The color code of a resistance is given below Yellow Violet Brown GoldThe values of resistance and tolerance, respectively, are


(1). 47 kΩ, 10%
(2). 4.7 kΩ, 5%
(3). 470 Ω, 5%
(4). 470 kΩ, 5%

Number of Attempts: 2

Correct Attempts: 1

Time Taken: 00:04

Average Time: 00:02

A charged particle having drift velocity of \(7.5 \times 10^{−4}\,ms^{−1}\) in an electric field of \(3 \times 10^{−10}\, V\, m^{−1}\), has a mobility in \(m^2\,V^{−1}\,s^{−1}\) of

(1). \(2.5 \times 10^6\)
(2). \(2.5 \times 10^{−6}\)
(3). \(2.25 \times 10^{−15}\)
(4). \(2.25 \times 10^{15}\)

Number of Attempts: 2

Correct Attempts: 1

Time Taken: 00:04

Average Time: 00:02

A resistance wire connected in the left gap of a metre bridge balances a \(10\, \Omega\) resistance in the right gap at a point which divides the bridge wire in the ratio \(3 : 2\). If the length of the resistance wire is \(1.5\, m\), then the length of \(1\, \Omega\) of the resistance wire is:

(1). \(1.0 \times 10^{−1}\,m\)
(2). \(1.5 \times 10{^−1}\,m\)
(3). \(1.5 \times 10^{−2}\,m\)
(4). \(1.0 \times 10^{−2}\,m\)

Number of Attempts: 2

Correct Attempts: 1

Time Taken: 00:04

Average Time: 00:02

Six similar bulbs are connected as shown in the figure with a DC source of emf E , and zero internal resistance. The ratio of power consumption by the bulbs when (i) all are glowing and (ii) in the situation when two from section A and one from section B are glowing, will be

(1). 2 : 1
(2). 4 : 9
(3). 9 : 4
(4). 1 : 2

Number of Attempts: 2

Correct Attempts: 1

Time Taken: 00:04

Average Time: 00:02

A set of n equal resistors, of value R each, are connected in series to abattery of emf E and internal resistance R. The current drawn is I .Now, the n resistors are connected in parallel to the same battery. Then the current drawn from battery becomes 10 I . The value of n is

(1). 10
(2). 11
(3). 20
(4). 9

Number of Attempts: 2

Correct Attempts: 1

Time Taken: 00:04

Average Time: 00:02

A battery consists of a variable number n of identical cells (havinginternal resistance r each ) which are connected in series. The terminals of the battery are short-circuited and the current I is measured. Whichof the graphs shows the correct relationship between I and n?

(1).
(2).
(3).
(4).

Number of Attempts: 2

Correct Attempts: 1

Time Taken: 00:04

Average Time: 00:02

A carbon resistor of (47 ± 4.7) kΩ is to be marked with rings of different colours for its identification. The colour code sequence will be

(1). Violet - Yellow - Orange - Silver
(2). Yellow - Violet - Orange - Silver
(3). Yellow - Green - Violet - Gold
(4). Green - Orange - Violet - Gold

Number of Attempts: 2

Correct Attempts: 1

Time Taken: 00:04

Average Time: 00:02

The resistance of a wire is 'R' ohm. If it is melted and stretched to 'n'times its original length, its new resistance will be

(1). \(\displaystyle \frac{R}{M}\)
(2). \(\displaystyle n^2\,R\)
(3). \(\displaystyle \frac{R}{n^2}\)
(4). \(nR\)

Number of Attempts: 2

Correct Attempts: 1

Time Taken: 00:04

Average Time: 00:02

A potentiometer is an accurate and versatile device to make electrical measurements of EMF because the method involves

(1). potential gradients
(2). a condition of no current flow through the galvanometer
(3). a combination of cells, galvanometer and resistances
(4). cells

Number of Attempts: 2

Correct Attempts: 1

Time Taken: 00:04

Average Time: 00:02

The charge flowing through a resistance R varies with time t as \(\text{Q}\, =\, at − bt^2\), where a and b are positive constants. The total heat produced in R is

(1). \(\displaystyle \frac{a^3R}{2b}\)
(2). \(\displaystyle \frac{a^3R}{b}\)
(3). \(\displaystyle \frac{a^3R}{6b}\)
(4). \(\displaystyle \frac{a^3R}{3b}\)

Number of Attempts: 2

Correct Attempts: 1

Time Taken: 00:04

Average Time: 00:02