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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.
| 7801. |
A single slit of width 0.20 mm is illuminated with light of wavelength 500 nm. The observing screen is placed 80 cm from the slit. The width of the central bright fringe will be [AMU (Med.) 2002] |
| A. | 1 mm |
| B. | 2 mm |
| C. | 4 mm |
| D. | 5 mm |
| Answer» D. 5 mm | |
| 7802. |
The light of wavelength\[6328\,\,{AA}\]is incident on a slit of width 0.2 mm perpendicularly, the angular width of central maxima will be [MP PMT 1987; Pb. PMT 2002] |
| A. | \[{{0.36}^{o}}\] |
| B. | \[{{0.18}^{o}}\] |
| C. | \[{{0.72}^{o}}\] |
| D. | \[{{0.09}^{o}}\] |
| Answer» B. \[{{0.18}^{o}}\] | |
| 7803. |
A slit of width\[a\]is illuminated by white light. For red light\[(\lambda =6500\,\,{AA})\], the first minima is obtained at\[\theta ={{30}^{o}}.\] Then the value of a will be [MP PMT 1987; CPMT 2002] |
| A. | \[3250\,\,{AA}\] |
| B. | \[6.5\times {{10}^{-4}}mm\] |
| C. | 1.24 microns |
| D. | \[2.6\times {{10}^{-4}}cm\] |
| Answer» D. \[2.6\times {{10}^{-4}}cm\] | |
| 7804. |
A voltmeter has a range 0-V with a series resistance R. With a series resistance 2R, the range is 0-V¢. The correct relation between V and V¢ is [CPMT 2001] |
| A. | \[{V}'=2V\] |
| B. | \[{V}'>2V\] |
| C. | \[{V}'>>2V\] |
| D. | \[V'<2V\] |
| Answer» E. | |
| 7805. |
In a potentiometer experiment two cells of e.m.f. E1 and E2 are used in series and in conjunction and the balancing length is found to be 58 cm of the wire. If the polarity of E2 is reversed, then the balancing length becomes 29 cm. The ratio \[\frac{{{E}_{1}}}{{{E}_{2}}}\] of the e.m.f. of the two cells is [Kerala (Engg.) 2001] |
| A. | 1 : 1 |
| B. | 2 : 1 |
| C. | 3 : 1 |
| D. | 4 : 1 |
| Answer» D. 4 : 1 | |
| 7806. |
A milliammeter of range 10 mA has a coil of resistance 1 W. To use it as voltmeter of range 10 volt, the resistance that must be connected in series with it, will be [KCET 2001] |
| A. | 999 W |
| B. | 99 W |
| C. | 1000 W |
| D. | None of these |
| Answer» B. 99 W | |
| 7807. |
A voltmeter having resistance of 50 × 103 ohm is used to measure the voltage in a circuit. To increase the range of measurement 3 times the additional series resistance required is [MP PET 2001] |
| A. | 105 ohm |
| B. | 150 k.ohm |
| C. | 900 k.ohm |
| D. | 9 × 106 ohm |
| Answer» B. 150 k.ohm | |
| 7808. |
In a circuit 5 percent of total current passes through a galvanometer. If resistance of the galvanometer is G then value of the shunt is [MP PET 2001] |
| A. | 19 G |
| B. | 20 G |
| C. | \[\frac{G}{20}\] |
| D. | \[\frac{G}{19}\] |
| Answer» E. | |
| 7809. |
An ammeter gives full deflection when a current of 2 amp. flows through it. The resistance of ammeter is 12 ohms. If the same ammeter is to be used for measuring a maximum current of 5 amp., then the ammeter must be connected with a resistance of [MP PET 2001] |
| A. | 8 ohms in series |
| B. | 18 ohms in series |
| C. | 8 ohms in parallel |
| D. | 18 ohms in parallel |
| Answer» D. 18 ohms in parallel | |
| 7810. |
AB is a potentiometer wire of length 100 cm and its resistance is 10 ohms. It is connected in series with a resistance R = 40 ohms and a battery of e.m.f. 2 V and negligible internal resistance. If a source of unknown e.m.f. E is balanced by 40 cm length of the potentiometer wire, the value of E is [MP PET 2001] |
| A. | 0.8 V |
| B. | 1.6 V |
| C. | 0.08 V |
| D. | 0.16 V |
| Answer» E. | |
| 7811. |
A potentiometer having the potential gradient of 2 mV/cm is used to measure the difference of potential across a resistance of 10 ohm. If a length of 50 cm of the potentiometer wire is required to get the null point, the current passing through the 10 ohm resistor is (in mA) [AMU (Med.) 2000] |
| A. | 1 |
| B. | 2 |
| C. | 5 |
| D. | 10 |
| Answer» E. | |
| 7812. |
Voltmeters V1 and V2 are connected in series across a D.C. line. V1 reads 80 volts and has a per volt resistance of 200 ohms. V2 has a total resistance of 32 kilo ohms. The line voltage is [UPSEAT 2000] |
| A. | 120 volts |
| B. | 160 volts |
| C. | 220 volts |
| D. | 240 volts |
| Answer» E. | |
| 7813. |
A galvanometer has 30 divisions and a sensitivity 16\[\mu A/\text{div}\text{.}\]It can be converted into a voltmeter to read 3 V by connecting [Kerala PMT 2005] |
| A. | Resistance nearly 6 \[k\,\Omega \]in series |
| B. | \[6\,k\,\Omega \] in parallel |
| C. | \[500\,\Omega \] in series |
| D. | It cannot be converted |
| Answer» B. \[6\,k\,\Omega \] in parallel | |
| 7814. |
By ammeter, which of the following can be measured [MP PET 1981; DPMT 2001] |
| A. | Electric potential |
| B. | Potential difference |
| C. | Current |
| D. | Resistance |
| Answer» D. Resistance | |
| 7815. |
In the circuit shown, a meter bridge is in its balanced state. The meter bridge wire has a resistance 0.1 ohm/cm. The value of unknown resistance X and the current drawn from the battery of negligible resistance is [AMU (Engg.) 2000] |
| A. | 6 W, 5 amp |
| B. | 10 W, 0.1 amp |
| C. | 4 W, 1.0 amp |
| D. | 12 W, 0.5 amp |
| Answer» D. 12 W, 0.5 amp | |
| 7816. |
A galvanometer has a resistance of 25 ohm and a maximum of 0.01 A current can be passed through it. In order to change it into an ammeter of range 10 A, the shunt resistance required is [MP PET 2000] |
| A. | 5/999 ohm |
| B. | 10/999 ohm |
| C. | 20/999 ohm |
| D. | 25/999 ohm |
| Answer» E. | |
| 7817. |
A galvanometer of 25 W resistance can read a maximum current of 6mA. It can be used as a voltmeter to measure a maximum of 6 V by connecting a resistance to the galvanometer. Identify the correct choice in the given answers [EAMCET (Med.) 2000] |
| A. | 1025 W in series |
| B. | 1025 W in parallel |
| C. | 975 W in series |
| D. | 975 W in parallel |
| Answer» D. 975 W in parallel | |
| 7818. |
The resistance of an ideal ammeter is [KCET 2000] |
| A. | Infinite |
| B. | Very high |
| C. | Small |
| D. | Zero |
| Answer» E. | |
| 7819. |
A galvanometer with a resistance of 12 W gives full scale deflection when a current of 3 mA is passed. It is required to convert it into a voltmeter which can read up to 18 V. the resistance to be connected is [Pb. PMT 2000] |
| A. | 6000 W |
| B. | 5988 W |
| C. | 5000 W |
| D. | 4988 W |
| Answer» C. 5000 W | |
| 7820. |
In the given figure, battery E is balanced on 55 cm length of potentiometer wire but when a resistance of 10 W is connected in parallel with the battery then it balances on 50 cm length of the potentiometer wire then internal resistance r of the battery is [DCE 2000; RPET 2000] |
| A. | 1 W |
| B. | 3 W |
| C. | 10 W |
| D. | 5 W |
| Answer» B. 3 W | |
| 7821. |
If an ammeter is connected in parallel to a circuit, it is likely to be damaged due to excess [BHU 2000; BCECE 2004] |
| A. | Current |
| B. | Voltage |
| C. | Resistance |
| D. | All of these |
| Answer» B. Voltage | |
| 7822. |
The resistance of a galvanometer coil is R. What is the shunt resistance required to convert it into an ammeter of range 4 times [BHU 2000] |
| A. | \[\frac{R}{5}\] |
| B. | \[\frac{R}{4}\] |
| C. | \[\frac{R}{3}\] |
| D. | 4 R |
| Answer» D. 4 R | |
| 7823. |
The ammeter A reads 2 A and the voltmeter V reads 20 V. the value of resistance R is (Assuming finite resistance's of ammeter and voltmeter) [JIPMER 1999; MP PMT 2004] |
| A. | Exactly 10 ohm |
| B. | Less than 10 ohm |
| C. | More than 10 ohm |
| D. | We cannot definitely say |
| Answer» D. We cannot definitely say | |
| 7824. |
In a balanced Wheatstone?s network, the resistances in the arms Q and S are interchanged. As a result of this [KCET 1999] |
| A. | Network is not balanced |
| B. | Network is still balanced |
| C. | Galvanometer shows zero deflection |
| D. | Galvanometer and the cell must be interchanged to balance |
| Answer» B. Network is still balanced | |
| 7825. |
An ammeter gives full scale deflection when current of 1.0 A is passed in it. To convert it into 10 A range ammeter, the ratio of its resistance and the shunt resistance will be [MP PMT 1985] |
| A. | 1 : 9 |
| B. | 1 : 10 |
| C. | 1 : 11 |
| D. | 9 : 1 |
| Answer» E. | |
| 7826. |
A potentiometer wire of length \[1\,m\] and resistance 10 W is connected in series with a cell of emf 2V with internal resistance 1 W and a resistance box including a resistance R. If potential difference between the ends of the wire is 1 mV, the value of R is [KCET 1999] |
| A. | 20000 W |
| B. | 19989 W |
| C. | 10000 W |
| D. | 9989 W |
| Answer» C. 10000 W | |
| 7827. |
The arrangement as shown in figure is called as [CPMT 1999] |
| A. | Potential divider |
| B. | Potential adder |
| C. | Potential substracter |
| D. | Potential multiplier |
| Answer» B. Potential adder | |
| 7828. |
For a cell of e.m.f. 2V, a balance is obtained for 50 cm of the potentiometer wire. If the cell is shunted by a \[2\,\Omega \] resistor and the balance is obtained across 40 cm of the wire, then the internal resistance of the cell is [SCRA 1998] |
| A. | \[0.25\,\Omega \] |
| B. | \[0.50\Omega \] |
| C. | \[0.80\,\Omega \] |
| D. | \[1.00\,\Omega \] |
| Answer» C. \[0.80\,\Omega \] | |
| 7829. |
A voltmeter has resistance of 2000 ohms and it can measure upto 2V. If we want to increase its range to 10 V, then the required resistance in series will be [CPMT 1997, SCRA 1994] |
| A. | \[2000\,\Omega \] |
| B. | \[4000\,\Omega \] |
| C. | \[6000\,\Omega \] |
| D. | \[8000\,\Omega \] |
| Answer» E. | |
| 7830. |
If the resistivity of a potentiometer wire be \[\rho \] and area of cross-section be A, then what will be potential gradient along the wire [RPET 1996] |
| A. | \[\frac{I\rho }{A}\] |
| B. | \[\frac{I}{A\rho }\] |
| C. | \[\frac{IA}{\rho }\] |
| D. | \[IA\rho \] |
| Answer» B. \[\frac{I}{A\rho }\] | |
| 7831. |
In the adjoining circuit, the e.m.f. of the cell is 2 volt and the internal resistance is negligible. The resistance of the voltmeter is 80 ohm. The reading of the voltmeter will be [CPMT 1991] |
| A. | 0.80 volt |
| B. | 1.60 volt |
| C. | 1.33 volt |
| D. | 2.00 volt |
| Answer» D. 2.00 volt | |
| 7832. |
We have a galvanometer of resistance \[25\,\Omega \]. It is shunted by a \[2.5\,\Omega \] wire. The part of total current that flows through the galvanometer is given as [AFMC 1998; MH CET 1999; Pb. PMT 2002] |
| A. | \[\frac{I}{{{I}_{0}}}=\frac{1}{11}\] |
| B. | \[\frac{I}{{{I}_{0}}}=\frac{1}{10}\] |
| C. | \[\frac{I}{{{I}_{0}}}=\frac{3}{11}\] |
| D. | \[\frac{I}{{{I}_{0}}}=\frac{4}{11}\] |
| Answer» B. \[\frac{I}{{{I}_{0}}}=\frac{1}{10}\] | |
| 7833. |
The resistance of 10 metre long potentiometer wire is 1ohm/meter. A cell of e.m.f. 2.2 volts and a high resistance box are connected in series to this wire. The value of resistance taken from resistance box for getting potential gradient of 2.2 millivolt/metre will be [RPET 1997] |
| A. | \[790\,\Omega \] |
| B. | \[810\,\Omega \] |
| C. | \[990\,\Omega \] |
| D. | \[1000\,\Omega \] |
| Answer» D. \[1000\,\Omega \] | |
| 7834. |
A voltmeter of resistance \[1000\,\Omega \] gives full scale deflection when a current of 100 mA flow through it. The shunt resistance required across it to enable it to be used as an ammeter reading 1 A at full scale deflection is [SCRA 1994] |
| A. | \[10000\,\Omega \] |
| B. | \[9000\,\Omega \] |
| C. | \[222\,\Omega \] |
| D. | \[111\,\Omega \] |
| Answer» E. | |
| 7835. |
In a potentiometer experiment, the galvanometer shows no deflection when a cell is connected across 60 cm of the potentiometer wire. If the cell is shunted by a resistance of \[6\,\Omega \], the balance is obtained across 50 cm of the wire. The internal resistance of the cell is [SCRA 1994] |
| A. | \[0.5\,\Omega \] |
| B. | \[0.6\,\Omega \] |
| C. | \[1.2\,\Omega \] |
| D. | \[1.5\,\Omega \] |
| Answer» D. \[1.5\,\Omega \] | |
| 7836. |
A 2 volt battery, a \[15\,\Omega \] resistor and a potentiometer of 100 cm length, all are connected in series. If the resistance of potentiometer wire is \[5\,\Omega \], then the potential gradient of the potentiometer wire is [AIIMS 1982] |
| A. | 0.005 V/cm |
| B. | 0.05 V/cm |
| C. | 0.02 V/cm |
| D. | 0.2 V/cm |
| Answer» B. 0.05 V/cm | |
| 7837. |
A galvanometer whose resistance is \[120\,\Omega \] gives full scale deflection with a current of 0.05 A so that it can read a maximum current of 10 A. A shunt resistance is added in parallel with it. The resistance of the ammeter so formed is [Bihar MEE 1995] |
| A. | \[0.06\,\Omega \] |
| B. | \[0.006\,\Omega \] |
| C. | \[0.6\,\Omega \] |
| D. | \[6\,\Omega \] |
| Answer» D. \[6\,\Omega \] | |
| 7838. |
An ammeter whose resistance is \[180\,\Omega \] gives full scale deflection when current is 2 mA. The shunt required to convert it into an ammeter reading 20 mA (in ohms) is [EAMCET (Engg.) 1995] |
| A. | 18 |
| B. | 20 |
| C. | 0.1 |
| D. | 10 |
| Answer» C. 0.1 | |
| 7839. |
A potentiometer wire has length 10 m and resistance \[20\,\Omega \]. A 2. 5 V battery of negligible internal resistance is connected across the wire with an \[80\,\Omega \] series resistance. The potential gradient on the wire will be [KCET 1994] |
| A. | \[5\times {{10}^{-5}}\,V/mm\] |
| B. | \[2.5\times {{10}^{-4}}\,V/cm\] |
| C. | \[0.62\times {{10}^{-4}}\,V/mm\] |
| D. | \[1\times {{10}^{-5}}\,V/mm\] |
| Answer» B. \[2.5\times {{10}^{-4}}\,V/cm\] | |
| 7840. |
A galvanometer having a resistance of 8 ohm is shunted by a wire of resistance 2 ohm. If the total current is 1 amp, the part of it passing through the shunt will be [CBSE PMT 1998] |
| A. | 0.25 amp |
| B. | 0.8 amp |
| C. | 0.2 amp |
| D. | 0.5 amp |
| Answer» C. 0.2 amp | |
| 7841. |
In the following Wheatstone bridge \[P/Q=R/S\]. If key K is closed, then the galvanometer will show deflection [CPMT 1999] |
| A. | In left side |
| B. | In right side |
| C. | No deflection |
| D. | In either side |
| Answer» E. | |
| 7842. |
In the circuit shown \[P\ne R\], the reading of the galvanometer is same with switch S open or closed. Then [IIT-JEE (Screening) 1999] |
| A. | \[{{I}_{R}}={{I}_{G}}\] |
| B. | \[{{I}_{P}}={{I}_{G}}\] |
| C. | \[{{I}_{Q}}={{I}_{G}}\] |
| D. | \[{{I}_{Q}}={{I}_{R}}\] |
| Answer» B. \[{{I}_{P}}={{I}_{G}}\] | |
| 7843. |
A galvanometer has resistance of \[7\,\Omega \] and gives a full scale deflection for a current of 1.0 A. How will you convert it into a voltmeter of range 10 V [MP PMT 1999] |
| A. | \[3\,\Omega \] in series |
| B. | \[3\,\Omega \] in parallel |
| C. | \[17\,\Omega \] in series |
| D. | \[30\,\Omega \] in series |
| Answer» B. \[3\,\Omega \] in parallel | |
| 7844. |
The net resistance of a voltmeter should be large to ensure that [MP PMT 1999] |
| A. | It does not get overheated |
| B. | It does not draw excessive current |
| C. | It can measure large potential difference |
| D. | It does not appreciably change the potential difference to be measured |
| Answer» E. | |
| 7845. |
\[50\,\Omega \] and \[100\,\Omega \] resistors are connected in series. This connection is connected with a battery of 2.4 volts. When a voltmeter of \[100\,\Omega \] resistance is connected across \[100\,\Omega \] resistor, then the reading of the voltmeter will be [MP PMT 1985] |
| A. | 1.6 V |
| B. | 1.0 V |
| C. | 1.2 V |
| D. | 2.0 V |
| Answer» D. 2.0 V | |
| 7846. |
Constantan wire is used in making standard resistances because its [MP PET 1999] |
| A. | Specific resistance is low |
| B. | Density is high |
| C. | Temperature coefficient of resistance is negligible |
| D. | Melting point is high |
| Answer» D. Melting point is high | |
| 7847. |
The resistance of an ideal voltmeter is [EAMCET (Med.) 1995; MP PMT/PET 1998; Pb. PMT 1999; CPMT 2000] |
| A. | Zero |
| B. | Very low |
| C. | Very large |
| D. | Infinite |
| Answer» E. | |
| 7848. |
If only 2% of the main current is to be passed through a galvanometer of resistance G, then the resistance of shunt will be [MP PMT/PET 1998] |
| A. | \[\frac{G}{50}\] |
| B. | \[\frac{G}{49}\] |
| C. | \[50\,G\] |
| D. | \[49\,G\] |
| Answer» C. \[50\,G\] | |
| 7849. |
. The resistivity of a potentiometer wire is \[40\times {{10}^{-8}}\,ohm-m\] and its area of cross-section is \[8\times {{10}^{-6}}\,{{m}^{2}}\]. If 0.2 amp current is flowing through the wire, the potential gradient will be [MP PMT/PET 1998] |
| A. | \[{{10}^{-2}}\,volt/m\] |
| B. | \[{{10}^{-1}}\,volt/m\] |
| C. | \[3.2\times {{10}^{-2}}\,volt/m\] |
| D. | \[1\,volt/m\] |
| Answer» B. \[{{10}^{-1}}\,volt/m\] | |
| 7850. |
A resistance of \[4\,\Omega \] and a wire of length 5 metres and resistance \[5\,\Omega \] are joined in series and connected to a cell of e.m.f. 10 V and internal resistance \[1\,\Omega \]. A parallel combination of two identical cells is balanced across 300 cm of the wire. The e.m.f. E of each cell is [MP PMT 1997] |
| A. | 1.5 V |
| B. | 3.0 V |
| C. | 0.67 V |
| D. | 1.33 V |
| Answer» C. 0.67 V | |