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MCQOPTIONS
This section includes 12583 Mcqs, each offering curated multiple-choice questions to sharpen your Joint Entrance Exam - Main (JEE Main) knowledge and support exam preparation. Choose a topic below to get started.
| 7851. |
The resistance of a galvanometer is 50 ohms and the current required to give full scale deflection is \[100\,\mu A\]. In order to convert it into an ammeter, reading upto 10A, it is necessary to put a resistance of [MP PMT 1997; AIIMS 1999] |
| A. | \[5\times {{10}^{-3}}\,\Omega \] in parallel |
| B. | \[5\times {{10}^{-4}}\,\Omega \] in parallel |
| C. | \[{{10}^{5}}\,\Omega \] in series |
| D. | \[99,950\,\Omega \]in series |
| Answer» C. \[{{10}^{5}}\,\Omega \] in series | |
| 7852. |
The figure shows a circuit diagram of a ?Wheatstone Bridge? to measure the resistance G of the galvanometer. The relation \[\frac{P}{Q}=\frac{R}{G}\] will be satisfied only when |
| A. | The galvanometer shows a deflection when switch S is closed |
| B. | The galvanometer shows a deflection when switch S is open |
| C. | The galvanometer shows no change in deflection whether S is open or closed |
| D. | The galvanometer shows no deflection |
| Answer» D. The galvanometer shows no deflection | |
| 7853. |
In the Wheatstone's bridge (shown in figure) \[X=Y\] and \[A>B\]. The direction of the current between ab will be |
| A. | From a to b |
| B. | From b to a |
| C. | From b to a through c |
| D. | From a to b through c |
| Answer» C. From b to a through c | |
| 7854. |
A galvanometer of \[100\,\Omega \] resistance gives full scale deflection when 10 mA of current is passed. To convert it into 10 A range ammeter, the resistance of the shunt required will be [MP PMT 1985] |
| A. | \[-10\,\Omega \] |
| B. | \[1\,\Omega \] |
| C. | \[0.1\,\Omega \] |
| D. | \[0.01\,\Omega \] |
| Answer» D. \[0.01\,\Omega \] | |
| 7855. |
In an experiment to measure the internal resistance of a cell by potentiometer, it is found that the balance point is at a length of 2m when the cell is shunted by a \[5\,\Omega \] resistance; and is at a length of 3m when the cell is shunted by a \[10\,\Omega \] resistance. The internal resistance of the cell is, then [Haryana CEE 1996] |
| A. | \[1.5\,\Omega \] |
| B. | \[10\,\Omega \] |
| C. | \[15\,\Omega \] |
| D. | \[1\,\Omega \] |
| Answer» C. \[15\,\Omega \] | |
| 7856. |
The circuit shown here is used to compare the e.m.f. of two cells \[{{E}_{1}}\] and \[{{E}_{2}}({{E}_{1}}>{{E}_{2}})\]. The null point is at C when the galvanometer is connected to \[{{E}_{1}}\]. When the galvanometer is connected to \[{{E}_{2}}\], the null point will be [MP PMT 1995] |
| A. | To the left of C |
| B. | To the right of C |
| C. | At C itself |
| D. | Nowhere on AB |
| Answer» B. To the right of C | |
| 7857. |
AB is a wire of uniform resistance. The galvanometer G shows no current when the length AC = 20cm and CB = 80 cm. The resistance R is equal to [MP PMT 1995; RPET 2001] |
| A. | \[2\,\Omega \] |
| B. | \[8\,\Omega \] |
| C. | \[20\,\Omega \] |
| D. | \[40\,\Omega \] |
| Answer» D. \[40\,\Omega \] | |
| 7858. |
An ammeter with internal resistance \[90\,\Omega \] reads 1.85 A when connected in a circuit containing a battery and two resistors 700\[\Omega \] and \[410\,\Omega \] in series. Actual current will be [Roorkee 1995] |
| A. | 1.85 A |
| B. | Greater than \[1.85\,A\] |
| C. | Less than 1.85 A |
| D. | None of these |
| Answer» C. Less than 1.85 A | |
| 7859. |
Which of the following is correct [BHU 1995] |
| A. | Ammeter has low resistance and is connected in series |
| B. | Ammeter has low resistance and is connected in parallel |
| C. | Voltmeter has low resistance and is connected in parallel |
| D. | None of the above |
| Answer» B. Ammeter has low resistance and is connected in parallel | |
| 7860. |
For comparing the e.m.f.'s of two cells with a potentiometer, a standard cell is used to develop a potential gradient along the wires. Which of the following possibilities would make the experiment unsuccessful [MP PMT 1994] |
| A. | The e.m.f. of the standard cell is larger than the E e.m.f.'s of the two cells |
| B. | The diameter of the wires is the same and uniform throughout |
| C. | The number of wires is ten |
| D. | The e.m.f. of the standard cell is smaller than the e.m.f.'s of the two cells |
| Answer» E. | |
| 7861. |
A voltmeter having a resistance of 998 ohms is connected to a cell of e.m.f. 2 volt and internal resistance 2 ohm. The error in the measurement of e.m.f. will be [MP PMT 1994] |
| A. | \[4\times {{10}^{-1}}\,volt\] |
| B. | \[2\times {{10}^{-3}}volt\] |
| C. | \[4\times {{10}^{-3}}volt\] |
| D. | \[2\times {{10}^{-1}}volt\] |
| Answer» D. \[2\times {{10}^{-1}}volt\] | |
| 7862. |
Which is a wrong statement [MP PMT 1994] |
| A. | The Wheatstone bridge is most sensitive when all the four resistances are of the same order |
| B. | In a balanced Wheatstone bridge, interchanging the positions of galvanometer and cell affects the balance of the bridge |
| C. | Kirchhoff's first law (for currents meeting at a junction in an electric circuit) expresses the conservation of charge |
| D. | The rheostat can be used as a potential divider |
| Answer» C. Kirchhoff's first law (for currents meeting at a junction in an electric circuit) expresses the conservation of charge | |
| 7863. |
The resistance of a galvanometer is 25 ohm and it requires \[50\,\mu A\] for full deflection. The value of the shunt resistance required to convert it into an ammeter of 5 amp is [MP PMT 1994; BHU 1997] |
| A. | \[2.5\times {{10}^{-4}}ohm\] |
| B. | \[1.25\times {{10}^{-3}}ohm\] |
| C. | 0.05 ohm |
| D. | 2.5 ohm |
| Answer» B. \[1.25\times {{10}^{-3}}ohm\] | |
| 7864. |
In a potentiometer circuit there is a cell of e.m.f. 2 volt, a resistance of 5 ohm and a wire of uniform thickness of length 1000 cm and resistance 15 ohm. The potential gradient in the wire is [MP PMT 1994] |
| A. | \[\frac{1}{500}V/cm\] |
| B. | \[\frac{3}{2000}V/cm\] |
| C. | \[\frac{3}{5000}V/cm\] |
| D. | \[\frac{1}{1000}V/cm\] |
| Answer» C. \[\frac{3}{5000}V/cm\] | |
| 7865. |
\[{{10}^{-3}}amp\] is flowing through a resistance of \[1000\,\Omega \]. To measure the correct potential difference, the voltmeter is to be used of which the resistance should be [MP PMT 1985] |
| A. | \[0\,\Omega \] |
| B. | \[500\,\Omega \] |
| C. | \[1000\,\Omega \] |
| D. | \[>>1000\,\Omega \] |
| Answer» E. | |
| 7866. |
The current flowing through a coil of resistance 900 ohms is to be reduced by 90%. What value of shunt should be connected across the coil [Roorkee 1992] |
| A. | \[90\,\Omega \] |
| B. | \[100\,\Omega \] |
| C. | \[9\,\Omega \] |
| D. | \[10\,\Omega \] |
| Answer» C. \[9\,\Omega \] | |
| 7867. |
A galvanometer of resistance \[25\,\Omega \] gives full scale deflection for a current of 10 milliampere, is to be changed into a voltmeter of range 100 V by connecting a resistance of ?R? in series with galvanometer. The value of resistance R in \[\Omega \] is [MP PET 1994] |
| A. | 10000 |
| B. | 10025 |
| C. | 975 |
| D. | 9975 |
| Answer» E. | |
| 7868. |
A moving coil galvanometer has a resistance of \[50\,\Omega \]and gives full scale deflection for 10 mA. How could it be converted into an ammeter with a full scale deflection for 1A [MP PMT 1996] |
| A. | \[50/99\,\Omega \] in series |
| B. | \[50/99\,\Omega \] in parallel |
| C. | \[0.01\,\Omega \] in series |
| D. | \[0.01\,\Omega \] in parallel |
| Answer» C. \[0.01\,\Omega \] in series | |
| 7869. |
In the diagram shown, the reading of voltmeter is 20 V and that of ammeter is 4 A. The value of R should be (Consider given ammeter and voltmeter are not ideal) [RPMT 1997] |
| A. | Equal to \[5\,\Omega \] |
| B. | Greater from \[5\,\Omega \] |
| C. | Less than \[5\,\Omega \] |
| D. | Greater or less than \[5\,\Omega \] depends on the material of R |
| Answer» D. Greater or less than \[5\,\Omega \] depends on the material of R | |
| 7870. |
Which of the following statement is wrong [MP PET 1994] |
| A. | Voltmeter should have high resistance |
| B. | Ammeter should have low resistance |
| C. | Ammeter is placed in parallel across the conductor in a circuit |
| D. | Voltmeter is placed in parallel across the conductor in a circuit |
| Answer» D. Voltmeter is placed in parallel across the conductor in a circuit | |
| 7871. |
Two cells when connected in series are balanced on 8m on a potentiometer. If the cells are connected with polarities of one of the cell is reversed, they balance on 2m. The ratio of e.m.f.'s of the two cells is |
| A. | \[3:5\] |
| B. | \[5:3\] |
| C. | \[3:4\] |
| D. | \[4:3\] |
| Answer» C. \[3:4\] | |
| 7872. |
The resistance of a galvanometer is 90 ohms. If only 10 percent of the main current may flow through the galvanometer, in which way and of what value, a resistor is to be used [MP PET 1996] |
| A. | 10 ohms in series |
| B. | 10 ohms in parallel |
| C. | 810 ohms in series |
| D. | 810 ohms in parallel |
| Answer» C. 810 ohms in series | |
| 7873. |
If in the experiment of Wheatstone's bridge, the positions of cells and galvanometer are interchanged, then balance points will |
| A. | Change |
| B. | Remain unchanged |
| C. | Depend on the internal resistance of cell and resistance of galvanometer |
| D. | None of these |
| Answer» C. Depend on the internal resistance of cell and resistance of galvanometer | |
| 7874. |
In the experiment of potentiometer, at balance, there is no current in the |
| A. | Main circuit |
| B. | Galvanometer circuit |
| C. | Potentiometer circuit |
| D. | Both main and galvanometer circuits |
| Answer» C. Potentiometer circuit | |
| 7875. |
A cell of internal resistance \[1.5\,\Omega \] and of e.m.f. 1.5 volt balances 500 cm on a potentiometer wire. If a wire of \[15\,\Omega \] is connected between the balance point and the cell, then the balance point will shift [MP PMT 1985] |
| A. | To zero |
| B. | By 500 cm |
| C. | By 750 cm |
| D. | None of the above |
| Answer» E. | |
| 7876. |
If the length of potentiometer wire is increased, then the length of the previously obtained balance point will |
| A. | Increase |
| B. | Decrease |
| C. | Remain unchanged |
| D. | Become two times |
| Answer» B. Decrease | |
| 7877. |
In an experiment of meter bridge, a null point is obtained at the centre of the bridge wire. When a resistance of 10 ohm is connected in one gap, the value of resistance in other gap is [MP PET 1994] |
| A. | \[10\,\Omega \] |
| B. | \[5\,\Omega \] |
| C. | \[\frac{1}{5}\Omega \] |
| D. | \[500\,\Omega \] |
| Answer» B. \[5\,\Omega \] | |
| 7878. |
Potential gradient is defined as [MP PET 1994] |
| A. | Fall of potential per unit length of the wire |
| B. | Fall of potential per unit area of the wire |
| C. | Fall of potential between two ends of the wire |
| D. | Potential at any one end of the wire |
| Answer» B. Fall of potential per unit area of the wire | |
| 7879. |
A potentiometer is used for the comparison of e.m.f. of two cells \[{{E}_{1}}\] and \[{{E}_{2}}\]. For cell \[{{E}_{1}}\] the no deflection point is obtained at 20\[cm\] and for \[{{E}_{2}}\] the no deflection point is obtained at 30\[cm\]. The ratio of their e.m.f.'s will be [MP PET 1984] |
| A. | 2/3 |
| B. | 1/2 |
| C. | 1 |
| D. | 2 |
| Answer» B. 1/2 | |
| 7880. |
A galvanometer of 10 ohm resistance gives full scale deflection with 0.01 ampere of current. It is to be converted into an ammeter for measuring 10 ampere current. The value of shunt resistance required will be [MP PET 1984] |
| A. | \[\frac{10}{999}\]ohm |
| B. | 0.1 ohm |
| C. | 0.5 ohm |
| D. | 1.0 ohm |
| Answer» B. 0.1 ohm | |
| 7881. |
A battery of 6 volts is connected to the terminals of a three metre long wire of uniform thickness and resistance of the order of 100\[\Omega \]. The difference of potential between two points separated by 50\[cm\] on the wire will be [CPMT 1984; CBSE PMT 2004] |
| A. | 1 V |
| B. | 1.5 V |
| C. | 2 V |
| D. | 3 V |
| Answer» B. 1.5 V | |
| 7882. |
A potentiometer is an ideal device of measuring potential difference because |
| A. | It uses a sensitive galvanometer |
| B. | It does not disturb the potential difference it measures |
| C. | It is an elaborate arrangement |
| D. | It has a long wire hence heat developed is quickly radiated |
| Answer» C. It is an elaborate arrangement | |
| 7883. |
Sensitivity of potentiometer can be increased by [MP PET 1994] |
| A. | Increasing the e.m.f. of the cell |
| B. | Increasing the length of the potentiometer wire |
| C. | Decreasing the length of the potentiometer wire |
| D. | None of the above |
| Answer» C. Decreasing the length of the potentiometer wire | |
| 7884. |
A Daniel cell is balanced on 125\[cm\] length of a potentiometer wire. Now the cell is short-circuited by a resistance 2 ohm and the balance is obtained at 100\[cm\]. The internal resistance of the Daniel cell is [UPSEAT 2002] |
| A. | 0.5 ohm |
| B. | 1.5 ohm |
| C. | 1.25 ohm |
| D. | 4/5 ohm |
| Answer» B. 1.5 ohm | |
| 7885. |
A galvanometer can be converted into an ammeter by connecting [MP PMT 1987, 93; CPMT 1973, 75, 96, 2000; MP PET 1994; AFMC 1993, 95; RPET 2000; DCE 2000] |
| A. | Low resistance in series |
| B. | High resistance in parallel |
| C. | Low resistance in parallel |
| D. | High resistance in series |
| Answer» D. High resistance in series | |
| 7886. |
In Wheatstone's bridge \[P=9\]ohm, \[Q=11\]ohm, \[R=4\]ohm and \[S=6\]ohm. How much resistance must be put in parallel to the resistance \[S\] to balance the bridge [DPMT 1999] |
| A. | 24 ohm |
| B. | \[\frac{44}{9}\]ohm |
| C. | 26.4 ohm |
| D. | 18.7 ohm |
| Answer» D. 18.7 ohm | |
| 7887. |
The tangent galvanometer, when connected in series with a standard resistance can be used as [MP PET 1994] |
| A. | An ammeter |
| B. | A voltmeter |
| C. | A wattmeter |
| D. | Both an ammeter and a voltmeter |
| Answer» C. A wattmeter | |
| 7888. |
A galvanometer can be used as a voltmeter by connecting a [AFMC 1993; MP PMT 1993, 95; CBSE PMT 2004] |
| A. | High resistance in series |
| B. | Low resistance in series |
| C. | High resistance in parallel |
| D. | Low resistance in parallel |
| Answer» B. Low resistance in series | |
| 7889. |
\[100\,mA\] current gives a full scale deflection in a galvanometer of \[2\,\Omega \] resistance. The resistance connected with the galvanometer to convert it into a voltmeter to measure \[5\,V\]is [MNR 1994; UPSEAT 2000] |
| A. | \[98\,\Omega \] |
| B. | \[52\,\Omega \] |
| C. | \[50\,\Omega \] |
| D. | \[48\,\Omega \] |
| Answer» E. | |
| 7890. |
Potentiometer wire of length 1 m is connected in series with 490\[\Omega \] resistance and 2V battery. If 0.2 mV/cm is the potential gradient, then resistance of the potentiometer wire is [DCE 2005] |
| A. | 4.9\[\Omega \] |
| B. | 7.9\[\Omega \] |
| C. | 5.9\[\Omega \] |
| D. | 6.9\[\Omega \] |
| Answer» B. 7.9\[\Omega \] | |
| 7891. |
If resistance of voltmeter is 10000W and resistance of ammeter is 2W then find R when voltmeter reads 12V and ammeter reads 0.1 A [BCECE 2005] |
| A. | 118 W |
| B. | 120 W |
| C. | 124 W |
| D. | 114W |
| Answer» B. 120 W | |
| 7892. |
Two resistances are connected in two gaps of a metre bridge. The balance point is 20 cm from the zero end. A resistance of 15 ohms is connected in series with the smaller of the two. The null point shifts to 40 cm. The value of the smaller resistance in ohms is [KCET 2005] |
| A. | 3 |
| B. | 6 |
| C. | 9 |
| D. | 12 |
| Answer» D. 12 | |
| 7893. |
A moving coil galvanometer of resistance 100W is used as an ammeter using a resistance 0.1W. The maximum deflection current in the galvanometer is 100mA. Find the minimum current in the circuit so that the ammeter shows maximum deflection [IIT-JEE (Screening) 2005] |
| A. | 100.1 mA |
| B. | 1000.1 mA |
| C. | 10.01 mA |
| D. | 1.01 mA |
| Answer» B. 1000.1 mA | |
| 7894. |
The potential gradient along the length of a uniform wire is \[10\,volt/metre\]. \[B\] and \[C\] are the two points at \[30\,cm\] and \[60\,cm\] point on a meter scale fitted along the wire. The potential difference between \[B\] and \[C\] will be [CPMT 1986] |
| A. | \[3\,volt\] |
| B. | \[0.4\,volt\] |
| C. | \[7\,volt\] |
| D. | \[4\,volt\] |
| Answer» B. \[0.4\,volt\] | |
| 7895. |
With a potentiometer null point were obtained at 140 cm and 180 cm with cells of emf 1.1 V and one unknown X volts. Unknown emf is [DCE 2002] |
| A. | 1.1 V |
| B. | 1.8 V |
| C. | 2.4 V |
| D. | 1.41 V |
| Answer» E. | |
| 7896. |
In a potentiometer experiment the balancing with a cell is at length 240 cm. On shunting the cell with a resistance of 2 W, the balancing length becomes 120 cm. The internal resistance of the cell is [DCE 2002; AIEEE 2005] |
| A. | 4 W |
| B. | 2 W |
| C. | 1 W |
| D. | 0.5 W |
| Answer» C. 1 W | |
| 7897. |
A voltmeter essentially consists of [UPSEAT 2004] |
| A. | A high resistance, in series with a galvanometer |
| B. | A low resistance, in series with a galvanometer |
| C. | A high resistance in parallel with a galvanometer |
| D. | A low resistance in parallel with a galvanometer |
| Answer» B. A low resistance, in series with a galvanometer | |
| 7898. |
A potentiometer consists of a wire of length 4 m and resistance 10 W. It is connected to cell of emf 2 V. The potential difference per unit length of the wire will be [Pb. PET 2002] |
| A. | 0.5 V/m |
| B. | 10 V/m |
| C. | 2 V/m |
| D. | 5 V/m |
| Answer» B. 10 V/m | |
| 7899. |
In given figure, the potentiometer wire AB has a resistance of 5 W and length 10 m. The balancing length AM for the emf of 0.4 V is [Pb. PET 2001] |
| A. | 0.4 m |
| B. | 4 m |
| C. | 0.8 m |
| D. | 8 m |
| Answer» E. | |
| 7900. |
In the circuit given, the correct relation to a balanced Wheatstone bridge is [Orissa PMT 2004] |
| A. | \[\frac{P}{Q}=\frac{R}{S}\] |
| B. | \[\frac{P}{Q}=\frac{S}{R}\] |
| C. | \[\frac{P}{R}=\frac{S}{Q}\] |
| D. | None of these |
| Answer» D. None of these | |