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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.
| 7901. |
In a metre bridge experiment null point is obtained at 20 cm from one end of the wire when resistance X is balanced against another resistance Y. If X < Y, then where will be the new position of the null point from the same end, if one decides to balance a resistance of 4X against Y [AIEEE 2004] |
| A. | 50 cm |
| B. | 80 cm |
| C. | 40 cm |
| D. | 70 cm |
| Answer» B. 80 cm | |
| 7902. |
A galvanometer of 50 ohm 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 [CBSE PMT 2004] |
| A. | 2500 W as a shunt |
| B. | 2450 W as a shunt |
| C. | 2550 W in series |
| D. | 2450 W in series |
| Answer» E. | |
| 7903. |
For the post office box arrangement to determine the value of unknown resistance the unknown resistance should be connected between [IIT-JEE (Screening) 2004] |
| A. | B and C |
| B. | C and D |
| C. | A and D |
| D. | B1 and C1 |
| Answer» D. B1 and C1 | |
| 7904. |
An ammeter of 5 ohm resistance can read 5 mA. If it is to be used to read 100 volts, how much resistance is to be connected in series [MP PET 1991; MP PMT 1996; MP PMT 2000] |
| A. | \[19.9995\,\Omega \] |
| B. | \[199.995\Omega \] |
| C. | \[1999.95\,\Omega \] |
| D. | \[19995\,\Omega \] |
| Answer» D. \[19995\,\Omega \] | |
| 7905. |
The current flowing in a coil of resistance 90 W is to be reduced by 90%. What value of resistance should be connected in parallel with it [MP PMT 2004] |
| A. | 9 W |
| B. | 90 W |
| C. | 1000 W |
| D. | 10 W |
| Answer» E. | |
| 7906. |
What is the reading of voltmeter in the following figure [MP PMT 2004] |
| A. | 3 V |
| B. | 2 V |
| C. | 5 V |
| D. | 4 V |
| Answer» E. | |
| 7907. |
The e.m.f. of a standard cell balances across 150 cm length of a wire of potentiometer. When a resistance of \[2\,\Omega \] is connected as a shunt with the cell, the balance point is obtained at \[100\,cm\]. The internal resistance of the cell is [MP PET 1993] |
| A. | \[0.1\,\Omega \] |
| B. | \[1\,\Omega \] |
| C. | \[2\,\Omega \] |
| D. | \[0.5\,\Omega \] |
| Answer» C. \[2\,\Omega \] | |
| 7908. |
Resistance of 100 cm long potentiometer wire is 10W, it is connected to a battery (2 volt) and a resistance R in series. A source of 10 mV gives null point at 40 cm length, then external resistance R is [MP PMT 2003] |
| A. | 490 W |
| B. | 790 W |
| C. | 590 W |
| D. | 990 W |
| Answer» C. 590 W | |
| 7909. |
The length of a wire of a potentiometer is 100 cm, and the emf of its standard cell is E volt. It is employed to measure the e.m.f of a battery whose internal resistance is 0.5 W. If the balance point is obtained at l = 30 cm from the positive end, the e.m.f. of the battery is [AIEEE 2003] |
| A. | \[\frac{30E}{100}\] |
| B. | \[\frac{30E}{100.5}\] |
| C. | \[\frac{30E}{(100-0.5)}\] |
| D. | \[\frac{30(E-0.5i)}{100}\], where i is the current in the potentiometer |
| Answer» B. \[\frac{30E}{100.5}\] | |
| 7910. |
An ammeter reads upto 1 ampere. Its internal resistance is 0.81 ohm. To increase the range to 10 A the value of the required shunt is [AIEEE 2003] |
| A. | 0.09 W |
| B. | 0.03 W |
| C. | 0.3 W |
| D. | 0.9 W |
| Answer» B. 0.03 W | |
| 7911. |
A galvanometer, having a resistance of 50 W gives a full scale deflection for a current of 0.05 A. The length in meter of a resistance wire of area of cross-section 2.97× 10?2 cm2 that can be used to convert the galvanometer into an ammeter which can read a maximum of 5 A current is (Specific resistance of the wire = 5 × \[{{10}^{-7}}\]Wm) [EAMCET 2003] |
| A. | 9 |
| B. | 6 |
| C. | 3 |
| D. | 1.5 |
| Answer» D. 1.5 | |
| 7912. |
Two resistances of 400 W and 800 W are connected in series with 6 volt battery of negligible internal resistance. A voltmeter of resistance 10,000 W is used to measure the potential difference across 400 W. The error in the measurement of potential difference in volts approximately is [EAMCET 2003] |
| A. | 0.01 |
| B. | 0.02 |
| C. | 0.03 |
| D. | 0.05 |
| Answer» E. | |
| 7913. |
A potentiometer has uniform potential gradient. The specific resistance of the material of the potentiometer wire is 10?7 ohm?meter and the current passing through it is 0.1 ampere; cross-section of the wire is 10?6 m2. The potential gradient along the potentiometer wire is [KCET 2003] |
| A. | \[{{10}^{-4}}\] V/m |
| B. | \[{{10}^{-6}}\] V/m |
| C. | \[{{10}^{-2}}\] V/m |
| D. | \[{{10}^{-8}}\] V/m |
| Answer» D. \[{{10}^{-8}}\] V/m | |
| 7914. |
In order to pass 10% of main current through a moving coil galvanometer of 99 ohm, the resistance of the required shunt is [MP PET 1990, 99; MP PMT 1994; RPET 2001; KCET 2003, 05] |
| A. | \[9.9\,\Omega \] |
| B. | \[10\,\Omega \] |
| C. | \[11\,\Omega \] |
| D. | \[9\,\Omega \] |
| Answer» D. \[9\,\Omega \] | |
| 7915. |
Resistance in the two gaps of a meter bridge are 10 ohm and 30 ohm respectively. If the resistances are interchanged the balance point shifts by [Orissa JEE 2003] |
| A. | 33.3 cm |
| B. | 66.67cm |
| C. | 25 cm |
| D. | 50 cm |
| Answer» E. | |
| 7916. |
If the ammeter in the given circuit reads 2 A, the resistance R is [Orissa JEE 2003] |
| A. | 1 ohm |
| B. | 2 ohm |
| C. | 3 ohm |
| D. | 4 ohm |
| Answer» B. 2 ohm | |
| 7917. |
A galvanometer of resistance 36 W is changed into an ammeter by using a shunt of 4 W. The fraction f0 of total current passing through the galvanometer is [BCECE 2003] |
| A. | \[\frac{1}{40}\] |
| B. | \[\frac{1}{4}\] |
| C. | \[\frac{1}{140}\] |
| D. | \[\frac{1}{10}\] |
| Answer» E. | |
| 7918. |
An ammeter of 100 W resistance gives full deflection for the current of 10?5 amp. Now the shunt resistance required to convert it into ammeter of 1 amp. range, will be [RPET 2003] |
| A. | \[{{10}^{-4}}\] W |
| B. | \[{{10}^{-5}}\] W |
| C. | \[{{10}^{-3}}\] W |
| D. | \[{{10}^{-1}}\] W |
| Answer» D. \[{{10}^{-1}}\] W | |
| 7919. |
A cell of internal resistance 3 ohm and emf 10 volt is connected to a uniform wire of length 500 cm and resistance 3 ohm. The potential gradient in the wire is [MP PET 2003] |
| A. | 30 mV/cm |
| B. | 10 mV/cm |
| C. | 20 mV/cm |
| D. | 4 mV/cm |
| Answer» C. 20 mV/cm | |
| 7920. |
The potential difference across the 100W resistance in the following circuit is measured by a voltmeter of 900 W resistance. The percentage error made in reading the potential difference is [AMU (Med.) 2002] |
| A. | \[\frac{10}{9}\] |
| B. | 0.1 |
| C. | 1.0 |
| D. | 10.0 |
| Answer» D. 10.0 | |
| 7921. |
A 100 ohm galvanometer gives full scale deflection at 10 mA. How much shunt is required to read 100 mA [MP PET 2002] |
| A. | 11.11 ohm |
| B. | 9.9 ohm |
| C. | 1.1 ohm |
| D. | 4.4 ohm |
| Answer» B. 9.9 ohm | |
| 7922. |
To convert a 800 mV range milli voltmeter of resistance 40 W into a galvanometer of 100 mA range, the resistance to be connected as shunt is [CBSE PMT 2002] |
| A. | 10 W |
| B. | 20 W |
| C. | 30 W |
| D. | 40 W |
| Answer» B. 20 W | |
| 7923. |
To convert a galvanometer into a voltmeter, one should connect a [CBSE PMT 2002] |
| A. | High resistance in series with galvanometer |
| B. | Low resistance in series with galvanometer |
| C. | High resistance in parallel with galvanometer |
| D. | Low resistance in parallel with galvanometer |
| Answer» B. Low resistance in series with galvanometer | |
| 7924. |
The material of wire of potentiometer is [MP PMT 2002] |
| A. | Copper |
| B. | Steel |
| C. | Manganin |
| D. | Aluminium |
| Answer» D. Aluminium | |
| 7925. |
A potentiometer has uniform potential gradient across it. Two cells connected in series (i) to support each other and (ii) to oppose each other are balanced over 6m and 2m respectively on the potentiometer wire. The e.m.f.?s of the cells are in the ratio of [MP PMT 2002] |
| A. | 1 : 2 |
| B. | 1 : 1 |
| C. | 3 : 1 |
| D. | 2 : 1 |
| Answer» E. | |
| 7926. |
A 10 m long wire of 20W resistance is connected with a battery of 3 volt e.m.f. (negligible internal resistance) and a 10 W resistance is joined to it is series. Potential gradient along wire in volt per meter is [MP PMT 2003] |
| A. | 0.02 |
| B. | 0.3 |
| C. | 0.2 |
| D. | 1.3 |
| Answer» D. 1.3 | |
| 7927. |
If an ammeter is to be used in place of a voltmeter then we must connect with the ammeter a [AIEEE 2002; AFMC 2002] |
| A. | Low resistance in parallel |
| B. | High resistance in parallel |
| C. | High resistance in series |
| D. | Low resistance in series |
| Answer» D. Low resistance in series | |
| 7928. |
There are three voltmeters of the same range but of resistances \[10000\,\Omega \], \[8000\,\Omega \] and \[4000\,\Omega \] respectively. The best voltmeter among these is the one whose resistance is [Kerala PET 2002] |
| A. | 10000 W |
| B. | 8000 W |
| C. | 4000 W |
| D. | All are equally good |
| Answer» B. 8000 W | |
| 7929. |
A galvanometer of resistance 20 W is to be converted into an ammeter of range 1 A. If a current of 1 mA produces full scale deflection, the shunt required for the purpose is [Kerala PET 2002] |
| A. | 0.01 W |
| B. | 0.05 W |
| C. | 0.02 W |
| D. | 0.04 W |
| Answer» D. 0.04 W | |
| 7930. |
A wire of length 100 cm is connected to a cell of emf 2 V and negligible internal resistance. The resistance of the wire is 3 W. The additional resistance required to produce a potential drop of 1 milli volt per cm is [Kerala PET 2002] |
| A. | 60 W |
| B. | 47 W |
| C. | 57 W |
| D. | 35 W |
| Answer» D. 35 W | |
| 7931. |
An ammeter and a voltmeter of resistance R are connected in series to an electric cell of negligible internal resistance. Their readings are A and V respectively. If another resistance R is connected in parallel with the voltmeter [EAMCET 2000; KCET 2002] |
| A. | Both A and V will increase |
| B. | Both A and V will decrease |
| C. | A will decrease and V will increase |
| D. | A will increase and V will decrease |
| Answer» E. | |
| 7932. |
A 36 W galvanometer is shunted by resistance of 4W. The percentage of the total current, which passes through the galvanometer is [UPSEAT 2002] |
| A. | 8 % |
| B. | 9 % |
| C. | 10 % |
| D. | 91 % |
| Answer» D. 91 % | |
| 7933. |
The resistance of 1 A ammeter is \[0.018\,\Omega \]. To convert it into 10 A ammeter, the shunt resistance required will be [MP PET 1982] |
| A. | \[0.18\,\Omega \] |
| B. | \[0.0018\,\Omega \] |
| C. | \[0.002\,\Omega \] |
| D. | \[0.12\,\Omega \] |
| Answer» D. \[0.12\,\Omega \] | |
| 7934. |
A simple pendulum has a time period \[{{T}_{1}}\] when on the earth?s surface and \[{{T}_{2}}\] when taken to a height R above the earth?s surface, where R is the radius of the earth. The value of \[{{T}_{2}}/{{T}_{1}}\] is [IIT-JEE 2001] |
| A. | 1 |
| B. | \[\sqrt{2}\] |
| C. | 4 |
| D. | 2 |
| Answer» E. | |
| 7935. |
A particle free to move along the x-axis has potential energy given by \[U(x)=k[1-\exp {{(-x)}^{2}}]\] for \[-\infty \le x\le +\infty \], where k is a positive constant of appropriate dimensions. Then [IIT-JEE 1999; UPSEAT 2003] |
| A. | At point away from the origin, the particle is in unstable equilibrium |
| B. | For any finite non-zero value of x, there is a force directed away from the origin |
| C. | If its total mechanical energy is k/2, it has its minimum kinetic energy at the origin |
| D. | For small displacements from x = 0, the motion is simple harmonic |
| Answer» E. | |
| 7936. |
A long horizontal rod has a bead which can slide along its length, and initially placed at a distance L from one end A of the rod. The rod is set in angular motion about A with constant angular acceleration a. If the coefficient of friction between the rod and the bead is m, and gravity is neglected, then the time after which the bead starts slipping is [IIT-JEE Screening 2000] |
| A. | \[\sqrt{\frac{\mu }{\alpha }}\] |
| B. | \[\frac{\mu }{\sqrt{\alpha }}\] |
| C. | \[\frac{1}{\sqrt{\mu \alpha }}\] |
| D. | Infinitesimal |
| Answer» B. \[\frac{\mu }{\sqrt{\alpha }}\] | |
| 7937. |
If the constant of gravitation \[(G)\], Planck's constant \[(h)\] and the velocity of light \[(c)\] be chosen as fundamental units. The dimension of the radius of gyration is [AMU (Eng.) 1999] |
| A. | \[{{h}^{1/2}}{{c}^{-3/2}}{{G}^{1/2}}\] |
| B. | \[{{h}^{1/2}}{{c}^{3/2}}{{G}^{1/2}}\] |
| C. | \[{{h}^{1/2}}{{c}^{-3/2}}{{G}^{-1/2}}\] |
| D. | \[{{h}^{-1/2}}{{c}^{-3/2}}{{G}^{1/2}}\] |
| Answer» B. \[{{h}^{1/2}}{{c}^{3/2}}{{G}^{1/2}}\] | |
| 7938. |
Current in the circuit will be [CBSE PMT 2001] |
| A. | \[\frac{5}{40}A\] |
| B. | \[\frac{5}{50}A\] |
| C. | \[\frac{5}{10}A\] |
| D. | \[\frac{5}{20}A\] |
| Answer» C. \[\frac{5}{10}A\] | |
| 7939. |
The modulation index of an FM carrier having a carrier swing of 200 kHz and a modulating signal 10 kHz is |
| A. | 5 |
| B. | 10 |
| C. | 20 |
| D. | 25 |
| Answer» C. 20 | |
| 7940. |
When a point source of monochromatic light is at a distance of 0.2 m from a photoelectric cell, the cut-off voltage and the saturation current are 0.6 volt and 18 mA respectively. If the same source is placed 0.6 m away from the photoelectric cell, then [IIT JEE 1992; MP PMT 1999] |
| A. | The stopping potential will be 0.2 V |
| B. | The stopping potential will be 0.6 V |
| C. | The saturation current will be 6 mA |
| D. | The saturation current will be 18 mA |
| Answer» C. The saturation current will be 6 mA | |
| 7941. |
A circular loop of radius R carrying current I lies in x-y plane with its centre at origin. The total magnetic flux through x-y plane is [IIT-JEE 1999] |
| A. | Directly proportional to I |
| B. | Directly proportional to R |
| C. | Directly proportional to \[{{R}^{2}}\] |
| D. | Zero |
| Answer» E. | |
| 7942. |
The diagram shows a capacitor C and a resistor R connected in series to an ac source. \[{{V}_{1}}\] and \[{{V}_{2}}\] are voltmeters and A is an ammeter Consider now the following statements I. Readings in A and V2 are always in phase II. Reading in V1 is ahead in phase with reading in V2 III. Readings in A and V1 are always in phase which of these statements are/is correct [AMU (Med.) 2001] |
| A. | I only |
| B. | II only |
| C. | I and II only |
| D. | II and III only |
| Answer» C. I and II only | |
| 7943. |
A cylindrical rod magnet has a length of 5 cm and a diameter of 1 cm. It has a uniform magnetisation of 5.30 × 103Amp/m3. What its magnetic dipole moment |
| A. | \[1\times {{10}^{-2}}J/T\] |
| B. | \[2.08\times {{10}^{-2}}J/T\] |
| C. | \[3.08\times {{10}^{-2}}J/T\] |
| D. | \[1.52\times {{10}^{-2}}J/T\] |
| Answer» C. \[3.08\times {{10}^{-2}}J/T\] | |
| 7944. |
A non-planar loop of conducting wire carrying a current I is placed as shown in the figure. Each of the straight sections of the loop is of length 2a. The magnetic field due to this loop at the point P (a,0,a) points in the direction [IIT-JEE (Screening) 2001] |
| A. | \[\frac{1}{\sqrt{2}}(-\overset{{}}{\mathop{\hat{j}+\hat{k}}}\,)\] |
| B. | \[\frac{1}{\sqrt{3}}(-\hat{j}+\hat{k}+\hat{i})\] |
| C. | \[\frac{1}{\sqrt{3}}(\hat{i}+\hat{j}+\hat{k})\] |
| D. | \[\frac{1}{\sqrt{2}}(\hat{i}+\hat{k})\] |
| Answer» E. | |
| 7945. |
A heater of 220 V heats a volume of water in 5 minute time. A heater of 110 V heats the same volume of water in [AFMC 1993] |
| A. | 5 minutes |
| B. | 8 minutes |
| C. | 10 minutes |
| D. | 20 minutes |
| Answer» E. | |
| 7946. |
Three rods of identical area of cross-section and made from the same metal form the sides of an isosceles triangle \[ABC\], right angled at \[B\]. The points \[A\] and \[B\] are maintained at temperatures \[T\] and \[\sqrt{2}T\] respectively. In the steady state the temperature of the point C is \[{{T}_{C}}\]. Assuming that only heat conduction takes place, \[\frac{{{T}_{C}}}{T}\] is equal to [IIT 1995] |
| A. | \[\frac{1}{(\sqrt{2}+1)}\] |
| B. | \[\frac{3}{(\sqrt{2}+1)}\] |
| C. | \[\frac{1}{2(\sqrt{2}-1)}\] |
| D. | \[\frac{1}{\sqrt{3}(\sqrt{2}-1)}\] |
| Answer» C. \[\frac{1}{2(\sqrt{2}-1)}\] | |
| 7947. |
An ideal gas expands isothermally from a volume \[{{V}_{1}}\] to \[{{V}_{2}}\] and then compressed to original volume \[{{V}_{1}}\]adiabatically. Initial pressure is \[{{P}_{1}}\] and final pressure is \[{{P}_{3}}\]. The total work done is W. Then [IIT-JEE (Screening) 2004] |
| A. | \[{{P}_{3}}>{{P}_{1}},\,\,W>0\] |
| B. | \[{{P}_{3}}<{{P}_{1}},\,\,W<0\] |
| C. | \[{{P}_{3}}>{{P}_{1}},\,\,W<0\] |
| D. | \[{{P}_{3}}={{P}_{1}},\,\,W=0\] |
| Answer» D. \[{{P}_{3}}={{P}_{1}},\,\,W=0\] | |
| 7948. |
A metal ball immersed in alcohol weighs \[{{W}_{1}}\] at 0°C and \[{{W}_{2}}\] at 59°C. The coefficient of cubical expansion of the metal is less than that of alcohol. Assuming that the density of metal is large compared to that of alcohol, it can be shown that [CPMT 1998] |
| A. | \[{{W}_{1}}>{{W}_{2}}\] |
| B. | \[{{W}_{1}}={{W}_{2}}\] |
| C. | \[{{W}_{1}}<{{W}_{2}}\] |
| D. | \[{{W}_{2}}=({{W}_{1}}/2)\] |
| Answer» D. \[{{W}_{2}}=({{W}_{1}}/2)\] | |
| 7949. |
A particle moves towards east with velocity 5 m/s. After 10 seconds its direction changes towards north with same velocity. The average acceleration of the particle is [CPMT 1997; IIT-JEE 1982] |
| A. | Zero |
| B. | \[\frac{1}{\sqrt{2}}\,m/{{s}^{2}}\,N-W\] |
| C. | \[\frac{1}{\sqrt{2}}\,m/{{s}^{2}}\,N-E\] |
| D. | \[\frac{1}{\sqrt{2}}\,m/{{s}^{2}}\,S-W\] |
| Answer» C. \[\frac{1}{\sqrt{2}}\,m/{{s}^{2}}\,N-E\] | |
| 7950. |
Two identical thin rings each of radius R meters are coaxially placed at a distance R meters apart. If Q1 coulomb and Q2 coulomb are respectively the charges uniformly spread on the two rings, the work done in moving a charge qfrom the centre of one ring to that of other is [MP PMT 1999; AMU (Engg.) 1999] |
| A. | Zero |
| B. | \[\frac{q({{Q}_{1}}-{{Q}_{2}})(\sqrt{2}-1)}{\sqrt{2}.4\pi {{\varepsilon }_{0}}R}\] |
| C. | \[\frac{q\sqrt{2}({{Q}_{1}}+{{Q}_{2}})}{4\pi {{\varepsilon }_{0}}R}\] |
| D. | \[\frac{q({{Q}_{1}}+{{Q}_{2}})(\sqrt{2}+1)}{\sqrt{2}.4\pi {{\varepsilon }_{0}}R}\] |
| Answer» C. \[\frac{q\sqrt{2}({{Q}_{1}}+{{Q}_{2}})}{4\pi {{\varepsilon }_{0}}R}\] | |