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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.
| 6001. |
4 bulbs marked 40 W, 250 V are connected in series with 250 V mains. The total power is [EAMCET (Engg.) 1995] |
| A. | 10 W |
| B. | 40 W |
| C. | 320 W |
| D. | 160 W |
| Answer» B. 40 W | |
| 6002. |
An electric lamp is marked 60 W, 230 V. The cost of 1 kilowatt hour of power is Rs. 1.25. The cost of using this lamp for 8 hours is [KCET 1994] |
| A. | Rs. 1.20 |
| B. | Rs. 4.00 |
| C. | Rs. 0.25 |
| D. | Rs. 0.60 |
| Answer» E. | |
| 6003. |
Watt-hour meter measures [KCET 1994] |
| A. | Electric energy |
| B. | Current |
| C. | Voltage |
| D. | Power |
| Answer» B. Current | |
| 6004. |
A \[5{}^\circ C\] rise in temperature is observed in a conductor by passing a current. When the current is doubled the rise in temperature will be approximately [CBSE PMT 1998] |
| A. | \[16{}^\circ C\] |
| B. | \[10{}^\circ C\] |
| C. | \[20{}^\circ C\] |
| D. | \[12{}^\circ C\] |
| Answer» D. \[12{}^\circ C\] | |
| 6005. |
Two electric bulbs whose resistances are in the ratio of 1 : 2 are connected in parallel to a constant voltage source. The powers dissipated in them have the ratio [NCERT 1977; MP PMT 1994, 2000] |
| A. | 1 : 2 |
| B. | 1 : 1 |
| C. | 2 : 1 |
| D. | 1 : 4 |
| Answer» D. 1 : 4 | |
| 6006. |
If 2.2 kilowatt power is transmitted through a 10 ohm line at 22000 volt, the power loss in the form of heat will be [MP PMT/PET 1998] |
| A. | 0.1 watt |
| B. | 1 watt |
| C. | 10 watt |
| D. | 100 watt |
| Answer» B. 1 watt | |
| 6007. |
A heating coil can heat the water of a vessel from \[20{}^\circ C\] to \[60{}^\circ C\] in 30 minutes. Two such heating coils are put in series and then used to heat the same amount of water through the same temperature range. The time taken now will be (neglecting thermal capacity of the coils) [MP PMT 1997] |
| A. | 60 minutes |
| B. | 30 minutes |
| C. | 15 minutes |
| D. | 7.5 minutes |
| Answer» B. 30 minutes | |
| 6008. |
Two conductors made of the same material are connected across a common potential difference. Conductor A has twice the diameter and twice the length of conductor B. The power delivered to the two conductors \[{{P}_{A}}\] and \[{{P}_{B}}\] respectively is such that \[{{P}_{A}}/{{P}_{B}}\] equals to |
| A. | 0.5 |
| B. | 1.0 |
| C. | 1.5 |
| D. | 2.0 |
| Answer» E. | |
| 6009. |
Two bulbs are working in parallel order. Bulb A is brighter than bulb B. If \[{{R}_{A}}\] and \[{{R}_{B}}\] are their resistance respectively then [MP PMT 2003] |
| A. | \[{{R}_{A}}>{{R}_{B}}\] |
| B. | \[{{R}_{A}}<{{R}_{B}}\] |
| C. | \[{{R}_{A}}={{R}_{B}}\] |
| D. | None of these |
| Answer» C. \[{{R}_{A}}={{R}_{B}}\] | |
| 6010. |
A 60 watt bulb carries a current of 0.5 amp. The total charge passing through it in 1 hour is [MP PMT 1996] |
| A. | 3600 coulomb |
| B. | 3000 coulomb |
| C. | 2400 coulomb |
| D. | 1800 coulomb |
| Answer» E. | |
| 6011. |
Two bulbs of 500 watt and 200 watt are manufactured to operate on 220 volt line. The ratio of heat produced in 500 W and 200 W, in two cases, when firstly they are joined in parallel and secondly in series, will be [MP PET 1996; DPMT 1999] |
| A. | \[\frac{5}{2},\,\frac{2}{5}\] |
| B. | \[\frac{5}{2},\,\frac{5}{2}\] |
| C. | \[\frac{2}{5},\,\frac{5}{2}\] |
| D. | \[\frac{2}{5},\,\frac{2}{5}\] |
| Answer» B. \[\frac{5}{2},\,\frac{5}{2}\] | |
| 6012. |
The energy consumed in 1 kilowatt electric heater in 30 seconds will be |
| A. | \[6\times {{10}^{2}}\,J\] |
| B. | \[4.99\times {{10}^{7}}\,J\] |
| C. | \[9.8\times {{10}^{6}}\,J\] |
| D. | \[3\times {{10}^{4}}\,J\] |
| Answer» E. | |
| 6013. |
Three light bulbs of 40 W, 60 W and 100 W are connected in series with 220 V source. Which one of the bulbs will glow brightest [MP PMT 1995; UPSEAT 2002; BCECE 2005] |
| A. | 40 W |
| B. | 60 W |
| C. | 100 W |
| D. | All with the same brightness |
| Answer» B. 60 W | |
| 6014. |
A heating coil is labelled 100 W, 220 V. The coil is cut in half and the two pieces are joined in parallel to the same source. The energy now liberated per second is [CBSE PMT 1995] |
| A. | 200 J |
| B. | 400 J |
| C. | 25 J |
| D. | 50 J |
| Answer» C. 25 J | |
| 6015. |
Which of the following is not a correct statement [MP PET 1995] |
| A. | Resistivity of electrolytes decreases on increasing temperature |
| B. | Resistance of mercury falls on decreasing its temperature |
| C. | When joined in series a 40 W bulb glows more than a 60 W bulb |
| D. | Resistance of 40 W bulb is less than the resistance of 60 W bulb |
| Answer» E. | |
| 6016. |
The internal resistance of a primary cell is 4 ohm. It generates a current of 0.2 amp in an external resistance of 21 ohm. The rate at which chemical energy is consumed in providing the current is [MP PMT 1994] |
| A. | \[0.42\,J/s\] |
| B. | \[0.84\,J/s\] |
| C. | \[5\,J/s\] |
| D. | \[1\,J/s\] |
| Answer» E. | |
| 6017. |
Resistances \[{{R}_{1}}\] and \[{{R}_{2}}\] are joined in parallel and a current is passed so that the amount of heat liberated is \[{{H}_{1}}\] and \[{{H}_{2}}\] respectively. The ratio \[\frac{{{H}_{1}}}{{{H}_{2}}}\] has the value [MP PMT 1994] |
| A. | \[\frac{{{R}_{2}}}{{{R}_{1}}}\] |
| B. | \[\frac{{{R}_{1}}}{{{R}_{2}}}\] |
| C. | \[\frac{R_{1}^{2}}{R_{2}^{2}}\] |
| D. | \[\frac{R_{2}^{2}}{R_{1}^{2}}\] |
| Answer» B. \[\frac{{{R}_{1}}}{{{R}_{2}}}\] | |
| 6018. |
A coil develops heat of 800 cal/sec. When 20 volts is applied across its ends. The resistance of the coil is (1 cal = 4.2 joule) [MP PET 1994] |
| A. | \[1.2\,\Omega \] |
| B. | \[1.4\,\Omega \] |
| C. | \[0.12\,\Omega \] |
| D. | \[0.14\,\Omega \] |
| Answer» D. \[0.14\,\Omega \] | |
| 6019. |
Electric power is transmitted over long distances through conducting wires at high voltage because [MP PET 1994] |
| A. | High voltage travels faster |
| B. | Power loss is large |
| C. | Power loss is less |
| D. | Generator produced electrical energy at a very high voltage |
| Answer» D. Generator produced electrical energy at a very high voltage | |
| 6020. |
The value of internal resistance of an ideal cell is [EAMCET 1989] |
| A. | Zero |
| B. | \[0.5\,\Omega \] |
| C. | \[1\,\Omega \] |
| D. | Infinity |
| Answer» B. \[0.5\,\Omega \] | |
| 6021. |
You are given three bulbs of 25, 40 and 60 watt. Which of them has lowest resistance [NCERT 1982] |
| A. | 25 watt bulb |
| B. | 40 watt bulb |
| C. | 60 watt bulb |
| D. | Information is insufficient |
| Answer» D. Information is insufficient | |
| 6022. |
Two resistances \[{{R}_{1}}\] and \[{{R}_{2}}\] when connected in series and parallel with 120 V line, power consumed will be 25 W and 100 W respectively. Then the ratio of power consumed by \[{{R}_{1}}\] to that consumed by \[{{R}_{2}}\] will be [EAMCET 1983] |
| A. | 1 : 1 |
| B. | 1 : 2 |
| C. | 2 : 1 |
| D. | 1 : 4 |
| Answer» B. 1 : 2 | |
| 6023. |
Forty electric bulbs are connected in series across a 220 V supply. After one bulb is fused, the remaining 39 are connected again in series across the same supply. The illumination will be [NCERT 1972; Haryana CEE 1996; DPMT 2001] |
| A. | More with 40 bulbs than with 39 |
| B. | More with 39 bulbs than with 40 |
| C. | Equal in both the cases |
| D. | In the ratio of \[{{49}^{2}}:{{39}^{2}}\] |
| Answer» C. Equal in both the cases | |
| 6024. |
There are two electric bulbs of 40 W and 100 W. Which one will be brighter when first connected in series and then in parallel, [MP PET 1993] |
| A. | 40 W in series and 100 W in parallel |
| B. | 100 W in series and 40 W in parallel |
| C. | 40 W both in series and parallel will be uniform |
| D. | 100 W both in series and parallel will be uniform |
| Answer» B. 100 W in series and 40 W in parallel | |
| 6025. |
The brightness of a bulb will be reduced, if a resistance is connected in |
| A. | Series with it |
| B. | Parallel with it |
| C. | Series or parallel with it |
| D. | Brightness of the bulb cannot be reduced |
| Answer» B. Parallel with it | |
| 6026. |
Two bulbs, one of 50 watt and another of 25 watt are connected in series to the mains. The ratio of the currents through them is [JIPMER 1997] |
| A. | 2 : 1 |
| B. | 1 : 2 |
| C. | 1 : 1 |
| D. | Without voltage, cannot be calculated |
| Answer» D. Without voltage, cannot be calculated | |
| 6027. |
The heat developed in an electric wire of resistance R by a current I for a time t is [MP PMT 1993; MP PET 2005] |
| A. | \[\frac{{{I}^{2}}Rt}{4.2}cal\] |
| B. | \[\frac{{{I}^{2}}t}{4.2R}cal\] |
| C. | \[\frac{{{I}^{2}}R}{4.2\,t}cal\] |
| D. | \[\frac{Rt}{4.2\,{{I}^{2}}}cal\] |
| Answer» B. \[\frac{{{I}^{2}}t}{4.2R}cal\] | |
| 6028. |
Two bulbs are in parallel and they together consume 48 W from a battery of 6 V. The resistance of each bulb is |
| A. | \[0.67\,\Omega \] |
| B. | \[3.0\,\Omega \] |
| C. | \[4.0\,\Omega \] |
| D. | \[1.5\,\Omega \] |
| Answer» E. | |
| 6029. |
The heat generated through 2 ohm and 8 ohm resistances separately, when a condenser of 200\[\mu F\] capacity charged to 200 V is discharged one by one, will be [MP PET 1993] |
| A. | 4 J and 16 J respectively |
| B. | 16 J and 4 J respectively |
| C. | 4 J and 8 J respectively |
| D. | 4 J and 4 J respectively |
| Answer» E. | |
| 6030. |
In the above question, the power lost in the cable during transmission is |
| A. | 12.5 kW |
| B. | 6.25 kW |
| C. | 25 kW |
| D. | 3.15 kW |
| Answer» C. 25 kW | |
| 6031. |
A cable of resistance \[10\,\Omega \] carries electric power from a generator producing 250 kW at 10000 volt. The current in the cable is |
| A. | 25 A |
| B. | 250 A |
| C. | 100 A |
| D. | 1000 A |
| Answer» B. 250 A | |
| 6032. |
An electric bulb of 100 watt is connected to a supply of electricity of 220 V. Resistance of the filament is [EAMCET 1981, 82; MP PMT 1993, 97] |
| A. | \[484\,\Omega \] |
| B. | \[100\,\Omega \] |
| C. | \[22000\,\Omega \] |
| D. | \[242\,\Omega \] |
| Answer» B. \[100\,\Omega \] | |
| 6033. |
The power rating of an electric motor which draws a current of 3.75 amperes when operated at 200 V is about |
| A. | 1 H.P. |
| B. | 500 W |
| C. | 54 W |
| D. | 750 H.P. |
| Answer» B. 500 W | |
| 6034. |
The two bulbs as in the above question are connected in series to a 200 volt line. Then [NCERT 1971, 78] |
| A. | The potential drop across the two bulbs is the same |
| B. | The potential drop across the 40 watt bulb is greater than the potential drop across the 100 watt bulb |
| C. | The potential drop across the 100 W bulb is greater than the potential drop across the 40 W bulb |
| D. | The potential drop across both the bulb is 200 volt |
| Answer» C. The potential drop across the 100 W bulb is greater than the potential drop across the 40 W bulb | |
| 6035. |
Heat produced in a wire of resistance R due to current flowing at constant potential difference is proportional to [MP PET 1993] |
| A. | \[\frac{1}{{{R}^{2}}}\] |
| B. | \[\frac{1}{R}\] |
| C. | R |
| D. | \[{{R}^{2}}\] |
| Answer» C. R | |
| 6036. |
An electric heater kept in vacuum is heated continuously by passing electric current. Its temperature [MP PET 1993] |
| A. | Will go on rising with time |
| B. | Will stop after sometime as it will loose heat to the surroundings by conduction |
| C. | Will rise for sometime and there after will start falling |
| D. | Will become constant after sometime because of loss of heat due to radiation |
| Answer» E. | |
| 6037. |
On an electric heater 220 volt and 1100 watt are marked. On using it for 4 hours, the energy consumed in kWh will be |
| A. | 2 |
| B. | 4.4 |
| C. | 6 |
| D. | 8 |
| Answer» C. 6 | |
| 6038. |
The heating coils rating at 220 volt and producing 50 cal/sec heat are available with the resistances \[55\,\Omega ,\ 110\,\Omega ,\ 220\,\Omega \] and \[440\,\Omega \]. The heater of maximum power will be of [MP PMT 1985] |
| A. | \[440\,\Omega \] |
| B. | \[220\,\Omega \] |
| C. | \[110\,\Omega \] |
| D. | \[55\,\Omega \] |
| Answer» E. | |
| 6039. |
A constant voltage is applied between the two ends of a metallic wire. If both the length and the radius of the wire are doubled, the rate of heat developed in the wire [MP PMT 1996] |
| A. | Will be doubled |
| B. | Will be halved |
| C. | Will remain the same |
| D. | Will be quadrupled |
| Answer» B. Will be halved | |
| 6040. |
Two identical batteries, each of e.m.f. 2 volt and internal resistance 1.0 ohm are available to produce heat in an external resistance \[R=0.5\]ohm by passing a current through it. The maximum Joulean power that can be developed across R using these batteries is [CBSE PMT 1990; BHU 1997] |
| A. | 1.28 watt |
| B. | 2.0 watt |
| C. | \[\frac{8}{9}\,watt\] |
| D. | 3.2 watt |
| Answer» C. \[\frac{8}{9}\,watt\] | |
| 6041. |
If current in an electric bulb changes by 1%, then the power will change by [AFMC 1996] |
| A. | 1% |
| B. | 2% |
| C. | 4% |
| D. | \[\frac{1}{2}%\] |
| Answer» C. 4% | |
| 6042. |
If two bulbs of wattage 25 and 100 respectively each rated at 220 volt are connected in series with the supply of 440 volt, then which bulbs will fuse [MNR 1988] |
| A. | 100 watt bulb |
| B. | 25 watt bulb |
| C. | None of them |
| D. | Both of them |
| Answer» C. None of them | |
| 6043. |
Two electric bulbs, one of 200 volt 40 watt and the other 200 volt 100 watt are connected in a house wiring circuit [NCERT 1971; CBSE PMT 2000] |
| A. | They have equal currents through them |
| B. | The resistance of the filaments in both the bulbs is same |
| C. | The resistance of the filament in 40 watt bulb is more than the resistance in 100 watt bulb |
| D. | The resistance of the filament in 100 watt bulb is more than the resistance in 40 watt bulb |
| Answer» D. The resistance of the filament in 100 watt bulb is more than the resistance in 40 watt bulb | |
| 6044. |
A 25 watt, 220 volt bulb and a 100 watt, 220 volt bulb are connected in parallel across a 220 volt line. Which bulb will glow more brightly |
| A. | 25 watt bulb |
| B. | 100 watt bulb |
| C. | Both will have same brightness |
| D. | First 25 watt then 100 watt |
| Answer» C. Both will have same brightness | |
| 6045. |
Two bulbs of equal wattage, one having carbon filament and the other having a tungsten filament are connected in series to the mains, then |
| A. | Both bulbs glow equally |
| B. | Carbon filament bulb glows more |
| C. | Tungsten filament bulbs glows more |
| D. | Carbon filament bulb glows less |
| Answer» D. Carbon filament bulb glows less | |
| 6046. |
Two identical heaters rated 220 volt, 1000 watt are placed in series with each other across 220 volt lines. If resistance do not change with temperature, then the combined power is |
| A. | 1000 watt |
| B. | 2000 watt |
| C. | 500 watt |
| D. | 4000 watt |
| Answer» D. 4000 watt | |
| 6047. |
Two heater wires of equal length are first connected in series and then in parallel. The ratio of heat produced in the two cases is [MNR 1987; UPSEAT 1999; MP PMT 1996, 2000, 01; AIIMS 2000; MP PET 1999, 2002; BHU 2004; Pb PET 2004] |
| A. | 2 : 1 |
| B. | 1 : 2 |
| C. | 4 : 1 |
| D. | 1 : 4 |
| Answer» E. | |
| 6048. |
According to Joule's law, if the potential difference across a conductor having a material of specific resistance remains constant, then the heat produced in the conductor is directly proportional to [MP PMT 1986] |
| A. | \[\rho \] |
| B. | \[{{\rho }^{2}}\] |
| C. | \[\frac{1}{\sqrt{\rho }}\] |
| D. | \[\frac{1}{\rho }\] |
| Answer» E. | |
| 6049. |
An electric fan and a heater are marked as 100 watt, 220 volt and 1000 watt, 220 volt respectively. The resistance of the heater is [CPMT 1990] |
| A. | Zero |
| B. | Greater than that of the fan |
| C. | Less than that of the fan |
| D. | Equal to that of the fan |
| Answer» D. Equal to that of the fan | |
| 6050. |
A resistor \[{{R}_{1}}\] dissipates the power P when connected to a certain generator. If the resistor \[{{R}_{2}}\] is put in series with \[{{R}_{1}}\], the power dissipated by \[{{R}_{1}}\] [CPMT 1985; MNR 1998] |
| A. | Decreases |
| B. | Increases |
| C. | Remains the same |
| D. | Any of the above depending upon the relative values of \[{{R}_{1}}\] and \[{{R}_{2}}\] |
| Answer» B. Increases | |