JEE Questions for Physics Current Electricity Ii Quiz 11 - MCQExams.com

Incandescent bulbs are designed by keeping in mind that the resistance of their filament increases with increase in temperature. If at room temperature, 100 W, 60 W and 40 W bulbs have filament resistances R100, R60 and R40 respectively, the relation between these resistances is

  • Physics-Current Electricity II-67195.png
  • 2)
    Physics-Current Electricity II-67196.png

  • Physics-Current Electricity II-67197.png

  • Physics-Current Electricity II-67198.png
A thermocouple of resistance 1.6 Ω is connected in series with a galvanometer of 8Ω resistance. The thermocouple develops an e.m.f. of 10 µV per degree temperature difference between two junctions. When one junction is kept at 0° C and the other in a molten metal, the galvanometer reads 8 millivolt. The temperature of molten metal, when e.m.f. varies linearly with temperature difference, will be
  • 960° C
  • 1050° C
  • 1275° C
  • 1545° C
The emf of a thermocouple, one junction of which is kept at 0°C, is given by e = at + bt2. The Peltier co-efficient will be
  • (t + 273)(a + 2bt)
  • (t + 273)(a – 2bt)
  • (t – 273)(a – 2bt)
  • (t – 273)(a + 2bt)
A coil of wire of resistance 50 Ω is embedded in a block of ice. If a potential difference of 210 V is applied across the coil, the amount of ice melted per second will be
  • 4.12 g
  • 4.12 kg
  • 3.68 kg
  • 2.625 g
The same mass of copper is drawn into two wires 1 mm and 2 mm thick. Two wires are connected in series and current is passed through them. Heat produced in the wire is in the ratio
  • 2 : 1
  • 1 : 16
  • 4 : 1
  • 16 : 1
The temperature of hot junction of a thermo-couple changes from 80° C to 100° C. The percentage change in thermoelectric power is
  • 8%
  • 10%
  • 20%
  • 25%
A thermocouple uses Bismuth and Tellurium as the dissimilar metals. The sensitivity of bismuth is –72g µV/°C and that of the tellurium is 500 µV/°C. If the difference between hot and cold junction is 100°C, then the maximum output will be
  • 50 mV
  • 7.2 mV
  • 42.8 mV
  • 57.2 mV
Three wires of copper, iron and nickel are joined to form three junctions as shown in Fig. When the temperature of junction 1 is kept 50° C with the other two junctions at 0°C, the sensitive galvanometer gives a deflection of 14 divisions. When the temperature of junction 3 is kept 50° C, with the other two junctions at 0°C, the galvanometer gives a deflection of 11 divisions. Then the deflection given by the galvanometer, when temperature of the junction 2 is kept at 50°C, with the other two junctions at 0° C, will be
Physics-Current Electricity II-67206.png
  • 3 div
  • 11 div
  • 14 div
  • 25 div
The wiring of a house has resistance 6 Ω. A 100 W bulb is glowing. If a geyser of 1000 W is switched on, the change in potential drop across the bulb is nearly when 220 V is the supplied voltage
  • Nil
  • 23 V
  • 32 V
  • 12 V
A 12 V lead accumulator is being charged using 24 V supply with an external resistance 2 Ω. The internal resistance of the accumulator is 1 Ω. Find the time in which it will store 360 W-hour energy
  • 1 hr
  • 7.5 hr
  • 10 hr
  • None of these
In a Ag voltameter 2.68 g of silver is deposited in 10 min. The heat developed in 20 Ω resistor during the same period will be
Physics-Current Electricity II-67209.png
  • 192 kJ
  • 192 J
  • 200 J
  • 132 kJ
The thermo e.m.f. of a thermocouple varies with the temperature θ of the hot junction as E = a θ + bθ2 in volts where the ratio a/b is 700° C. If the cold junction is kept at 0° C, then the neutral temperature is
  • 700° C
  • 350° C
  • 1400° C
  • No neutral temperature is possible for this thermocouple
In the following circuit, 5 Ω resistor develops 45 J/s due to current flowing through it. The power developed per second across 12 Ω resistor is
Physics-Current Electricity II-67212.png
  • 16 W
  • 192 W
  • 36 W
  • 64 W
Water of volume 2 litre in a container is heated with a coil of 1 kW at 27° C. The lid of the container is open and energy dissipates at rate of 160 J/s. In how much time temperature will rise from 27° C to 77°C [Given specific heat of water is 4.2 kJ/kg]
  • 8 min 20 s
  • 6 min 2 s
  • 7 min
  • 14 min
In a copper voltameter, mass deposited in 30 second is `m\' g. If the time-current graph is as shown in figure, ECE of copper is
Physics-Current Electricity II-67215.png
  • m
  • m/2
  • 0.1 m
  • 0.6 m
Which of the following plots may represent the thermal energy produced in a resistor in a given time as a function of the electric current? U
Physics-Current Electricity II-67217.png
  • a
  • b
  • c
  • d
Two different metals are joined end to end. One end is kept at constant temperature and the other end is heated to a very high temperature. The graph depicting the thermo e.m.f. is

  • Physics-Current Electricity II-67219.png
  • 2)
    Physics-Current Electricity II-67220.png

  • Physics-Current Electricity II-67221.png

  • Physics-Current Electricity II-67222.png
Which of the following graphs shows the variation of thermoelectric power with temperature difference between hot and cold junction in thermocouples?

  • Physics-Current Electricity II-67224.png
  • 2)
    Physics-Current Electricity II-67225.png

  • Physics-Current Electricity II-67226.png

  • Physics-Current Electricity II-67227.png
When an electric heater is switched on, the current flowing through it (i ) is plotted against time (t). Taking into account the variation of resistance with temperature, which of the following best represent the resulting curve?

  • Physics-Current Electricity II-67229.png
  • 2)
    Physics-Current Electricity II-67230.png

  • Physics-Current Electricity II-67231.png

  • Physics-Current Electricity II-67232.png
The V-i graphs A and B are drawn for two voltameters. Identify each graph
Physics-Current Electricity II-67233.png
  • A for water voltameter and B for Cu voltameter
  • A for Cu voltameter and B for water voltameter
  • Both A and B represents Cu voltameter
  • None of the above
A constant current i is passed through a resistor. Taking the temperature coefficient of resistance into account, indicate which of the plots shown in figure best represents the rate of production of thermal energy in the resistor
Physics-Current Electricity II-67234.png
  • a
  • b
  • c
  • d
In a copper voltameter, mass deposited in 6 minutes is m gram. If the current-time graph for the voltameter is as shown here, then the E.C.E. of the copper is
Physics-Current Electricity II-67236.png
  • m/5
  • m/300
  • 5 m
  • m/18000
Battery shown in figure has e.m.f. E and internal resistance r. Current in the circuit can be varied by sliding the contact J. If at any instant current flowing through the circuit is I, potential difference between terminals of the cell is V, thermal power generated in the cell is equal to i fraction of total electrical power generated in it; then which of the following graphs is correct?
Physics-Current Electricity II-67238.png

  • Physics-Current Electricity II-67239.png
  • 2)
    Physics-Current Electricity II-67240.png

  • Physics-Current Electricity II-67241.png
  • Both (a) and (b) are correct
A steel wire has a resistance twice that of an aluminium wire. Both of them are connected with a constant voltage supply. More heat will be dissipated in
  • Steel wire when both are connected in series
  • Steel wire when both are connected in parallel
  • Aluminium wire when both are connected in series
  • Aluminium wire when both are connected in parallel
Assertion The possibility of an electric bulb fusing is higher at the time of switching ON and OFF.
Reason Inductive effects produce a surge at the time of switch ON and OFF.
  • If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion
  • If both Assertion and Reason are true but Reason is not the correct explanation of the Assertion
  • If Assertion is true but Reason is false
  • If the Assertion and Reason both are false
  • If Assertion is false but Reason is true
Assertion The 200 W bulbs glow with more brightness than 100 W bulbs.
Reason A 100 W bulb has more resistance than a 200 W bulb.
  • If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion
  • If both Assertion and Reason are true but Reason is not the correct explanation of the Assertion
  • If Assertion is true but Reason is false
  • If the Assertion and Reason both are false
  • If Assertion is false but Reason is true
Assertion Fuse wire must have high resistance and low melting point.
Reason Fuse is used for small current flow only.
  • If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion
  • If both Assertion and Reason are true but Reason is not the correct explanation of the Assertion
  • If Assertion is true but Reason is false
  • If the Assertion and Reason both are false
  • If Assertion is false but Reason is true
Assertion Two electric bulbs of 50 and 100 W are given. When connected in series 50 W bulb glows more but when connected parallel 100 W bulb glows more.
Reason In series combination, power is directly proportional to the resistance of circuit. But in parallel combination, power is inversely proportional to the resistance of the circuit.
  • If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion
  • If both Assertion and Reason are true but Reason is not the correct explanation of the Assertion
  • If Assertion is true but Reason is false
  • If the Assertion and Reason both are false
  • If Assertion is false but Reason is true
Assertion Two bulbs of same wattage, one having a carbon filament and the other having a metallic filament are connected in series. Metallic bulbs will glow more brightly than carbon filament bulb.
Reason Carbon is a semiconductor.
  • If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion
  • If both Assertion and Reason are true but Reason is not the correct explanation of the Assertion
  • If Assertion is true but Reason is false
  • If the Assertion and Reason both are false
  • If Assertion is false but Reason is true
Assertion An electric bulb is first connected to a D.C. source and then to an A.C. source having the same brightness in both the cases.
Reason The peak value of voltage for an A.C. source is √2 times the root mean square voltage.
  • If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion
  • If both Assertion and Reason are true but Reason is not the correct explanation of the Assertion
  • If Assertion is true but Reason is false
  • If the Assertion and Reason both are false
  • If Assertion is false but Reason is true
Assertion An electric bulb becomes dim, when an electric heater in parallel circuit is switched on.
Reason Dimness decreases after sometime.
  • If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion
  • If both Assertion and Reason are true but Reason is not the correct explanation of the Assertion
  • If Assertion is true but Reason is false
  • If the Assertion and Reason both are false
  • If Assertion is false but Reason is true
Assertion Though the same current flows through the line wires and the filament of the bulb but heat produced in the filament is much higher than that in line wires.
Reason The filament of bulbs is made of a material of high resistance and high melting point.
  • If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion
  • If both Assertion and Reason are true but Reason is not the correct explanation of the Assertion
  • If Assertion is true but Reason is false
  • If the Assertion and Reason both are false
  • If Assertion is false but Reason is true
Assertion Neutral temperature of a thermocouple does not depend upon temperature of cold junction.
Reason Its value is constant for the given metals of the couple.
  • If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion
  • If both Assertion and Reason are true but Reason is not the correct explanation of the Assertion
  • If Assertion is true but Reason is false
  • If the Assertion and Reason both are false
  • If Assertion is false but Reason is true
Assertion When temperature of cold junction of a thermocouple is lowered, the value of neutral temperature of this thermocouple is raised.
Reason When the difference of temperature of two junctions is raised, more thermo e.m.f. is produced.
  • If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion
  • If both Assertion and Reason are true but Reason is not the correct explanation of the Assertion
  • If Assertion is true but Reason is false
  • If the Assertion and Reason both are false
  • If Assertion is false but Reason is true
Assertion Leclanche cell is used when constant supply of electric current is not required.
Reason The e.m.f. of a Leclanche cell falls if it is used continuously.
  • If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion
  • If both Assertion and Reason are true but Reason is not the correct explanation of the Assertion
  • If Assertion is true but Reason is false
  • If the Assertion and Reason both are false
  • If Assertion is false but Reason is true
Assertion In the given circuit if lamp B or C fuses then light emitted by lamp A decreases.
ReasonVoltage on A decreases.
Physics-Current Electricity II-67250.png
  • If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion
  • If both Assertion and Reason are true but Reason is not the correct explanation of the Assertion
  • If Assertion is true but Reason is false
  • If the Assertion and Reason both are false
  • If Assertion is false but Reason is true
Assertion If three identical bulbs are connected in series as shown in figure, then on closing the switch bulb C is short circuited and hence illumination of bulbs A and B decreases.
Reason Voltage on A and B decreases.
Physics-Current Electricity II-67251.png
  • If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion
  • If both Assertion and Reason are true but Reason is not the correct explanation of the Assertion
  • If Assertion is true but Reason is false
  • If the Assertion and Reason both are false
  • If Assertion is false but Reason is true
Assertion Heat is generated continuously is an electric heater but its temperature becomes constant after some time.
Reason At the stage when heat produced in heater is equal to the heat dissipated to its surrounding the temperature of heater becomes constant.
  • If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion
  • If both Assertion and Reason are true but Reason is not the correct explanation of the Assertion
  • If Assertion is true but Reason is false
  • If the Assertion and Reason both are false
  • If Assertion is false but Reason is true
Assertion Electric appliances with metallic body; e.g., heaters, presses etc, have three pin connections, whereas an electric bulb has a two pin connection.
ReasonThree pin connections reduce heating of connecting cables.
  • If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion
  • If both Assertion and Reason are true but Reason is not the correct explanation of the Assertion
  • If Assertion is true but Reason is false
  • If the Assertion and Reason both are false
  • If Assertion is false but Reason is true
Assertion A laser beam of 0.2 W power can drill holes through a metal sheet, whereas 1000 W torch¬light cannot.
Reason The frequency of laser light is much higher than that of torch light.
  • If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion
  • If both Assertion and Reason are true but Reason is not the correct explanation of the Assertion
  • If Assertion is true but Reason is false
  • If the Assertion and Reason both are false
  • If Assertion is false but Reason is true
Assertion A domestic electrical appliance, working on a three pin will continue working even if the top pin is removed.
Reason The third pin is used only as a safety device.
  • If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion
  • If both Assertion and Reason are true but Reason is not the correct explanation of the Assertion
  • If Assertion is true but Reason is false
  • If the Assertion and Reason both are false
  • If Assertion is false but Reason is true
Assertion In all conductors, for studying the thermoelectric behaviour of metals, lead is taken as a reference metal.
Reason In lead, the Thomson effect is negative.
  • If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion
  • If both Assertion and Reason are true but Reason is not the correct explanation of the Assertion
  • If Assertion is true but Reason is false
  • If the Assertion and Reason both are false
  • If Assertion is false but Reason is true
Assertion Thermocouple acts as a heat engine.
Reason When two junctions of thermocouple are at different temperature, thermo e.m.f. is produced
  • If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion
  • If both Assertion and Reason are true but Reason is not the correct explanation of the Assertion
  • If Assertion is true but Reason is false
  • If the Assertion and Reason both are false
  • If Assertion is false but Reason is true
Two bulbs consume same power when operated at 200 V and 300 V respectively. When these bulbs are connected in series across a D.C. source of 500 V, then
  • Ratio of potential difference across them is 3/2
  • Ratio of potential difference across them is 9/4
  • Ratio of power consumed across them is 4/9
  • Ratio of power consumed across them is 2/3
A 3° C rise in temperature is observed in a conductor by passing certain current. When the current is doubled, the rise in temperature will be
  • 15° C
  • 12° C
  • 9° C
  • 3 ° C
Two identical electric lamps marked 500 W, 220 V are connected in series and then joined to a 110 V line. The power consumed by each lamp is

  • Physics-Current Electricity II-67254.png
  • 2)
    Physics-Current Electricity II-67255.png

  • Physics-Current Electricity II-67256.png
  • 125 W
When 1 g hydrogen (e.c.e. = 1.044 × 10–8 kg/C) forms water, 34 kcal heat is liberated. The minimum voltage required to decompose water is
  • 0.75 V
  • 3 V
  • 1.5 V
  • 4.5 V
Total surface area of a cathode is 0.05 m2 and 1 A current passes through it for 1 hour. Thickness of nickle deposited on the cathode is (Given that density of nickle = 9 g/cc and it\'s E.C.E. = 3.04 × 10–4 g/C)
  • 2.4 m
  • 0.24 µm
  • 2.4 µm
  • None of these
Three resistances A, B and C have values 3R, 6R and R respectively. When some potential difference is applied across the network, the thermal powers dissipated by A, B and C are in the ratio
Physics-Current Electricity II-67260.png
  • 2 : 3 : 4
  • 2 : 4 : 3
  • 4 : 2 : 3
  • 3 : 2 : 4
If the length of the filament of a heater is reduced by 10% the power of the heater will
  • Increase by about 9%
  • Increase by about 11%
  • Increase by about 19%
  • Decrease by about 10%
0:0:1


Answered Not Answered Not Visited Correct : 0 Incorrect : 0

Practice Physics Quiz Questions and Answers