JEE Questions for Physics Current Electricity Ii Quiz 4

Which is the dimensional formula for condutance from the give below?

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Physics-Current Electricity II-66532.png

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500 m
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5000 m
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20,000 m
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How would you arrange 48 cells each of e.m.f 2V and internal resistance 1.5Ω so as to pass maximum current through the external resistance of 2Ω ?

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2 cells in 24 groups
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4 cells in 12 groups
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8 cells in 6 groups
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3 cells in 16 groups

How many dry cells, each of emf 1.5V and internal resistance 0.5Ω, much be joined in series with a resistor of 20Ω to give a current of 0.6A in the circuit ?

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2
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8
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10
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12

Two electirc bulbs whose resistances are in the ratio of 1:2 are connected in parallel to a constant voltage source the power dissipated in them have the ratio.

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1 : 2
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1 : 1
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2 : 1
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1 : 4

If the above two bulbs are connected in series, the power dissipatd in them have the ratio:

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1 : 2
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1 : 1
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2 : 1
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1 : 4

An electric kettle has two coils. when once of them is switched on, the water in the kettle boils in 6 minutes. When the other coil is switched on, the water boils in 3 minutes If the two coils are connected in series the time taken to boil water in the kettle is:

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3 minutes
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6 minutes
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2 minutes
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9 minutes

An electric kettle has two coils when one of these is switched on. the water in the kettle boils in 6 minutes. When the other coil is switched on, boils in 3 minutes If the two coils are connected in parallel, the time taken to boil water in the kettle is.

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3 minutes
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6 minutes
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2 minutes
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9 minutes

The potential difference between the terminals of a battery is 10V and internal resistance 1Ω drops to 8V when connected across an external resistor find the resistance of the external resistor.

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40 Ω
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0.4 Ω
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4M Ω
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4 Ω

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....

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2 : 1
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1 : 2
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4 : 1
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1 : 4

A heater boils 1kg of water in time 1 t and another heater boils the same water in time t₂ If both are connected in series, the combination will boil the same water in time.

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The drift velocity of free electrons in a conductor is v, when a current. I is flowing in it If both the radius and current are doubled, then drift velocity will be.

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4V
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2V

Physics-Current Electricity II-66548.png

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400o C
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450o C
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500o C
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550o C

Physics-Current Electricity II-66550.png

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5 Ω
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4 Ω
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3 Ω
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2 Ω

There are n resistors having equal value of resistance r. First they are connected in such a way that the possible minimum value of resistance is obtained. Then they are connected in such a way that possible maximum value of resistance is obtained the ratio of minimum and maximum values of resistances obtained in these way is....

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Temperature of a conductor increases by 5^o C passing electric current for some time. The increase in its temperature when double current is passed through the same conductor for the same time is.... ^o C

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10
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12
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16
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20

Area of cross-section of two wires of same length carrying same current is in the ratio of 1 : 2. Then the ratio of heat generated per second in the wires = ....

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1 : 1
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1 : 4
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2 : 1

Physics-Current Electricity II-66560.png

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None of these

Physics-Current Electricity II-66565.png

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8C
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18C
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20C
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24C

when current flowing through a conductor is I, average drift velocity of free electrons is V_d. Now when 6I current is flowing through a conductor having 3 times cross sectional are of same material what will be average dirft velocity of free electrons?

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n resistors each of resistance r are connected to a battery of emf E and internal resistance r. Then the ratio of terminal voltage to emf of battery =....

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Masses of three conductors of same material are in the proportion of 1:2:3 their lengths are in the proportion of 3:2:1 then their resistance will be in the proportion of....

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1 : 1 : 1
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1 : 2 : 3
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9 : 4 : 1
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27 : 6 : 1

Physics-Current Electricity II-66578.png

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4 Ω
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3 Ω
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2 Ω
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1 Ω

Physics-Current Electricity II-66580.png

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0%
2)
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0%

A bulb of 300W and 220V is connected with a source of 110V. What is the % decrease in power?

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100%
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75%
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70%
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25%

Length of a heating filament is reduced by 20% its power will...

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Decrease by 20%
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Increaseby 20%
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Increase by 25%
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Incease by 40%

What maximum power can be obtained from a battery of emf ε and internal resistance r connected with an external resistance R?

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0%

Physics-Current Electricity II-66591.png

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2160 K
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1800 K
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2070 K
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2300 K

Physics-Current Electricity II-66593.png

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2)
0%
0%

Physics-Current Electricity II-66599.png

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1400 K
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1200 K
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1000 K
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800 K

Physics-Current Electricity II-66601.png

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2 Ω and 0.5 Ω
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1 Ω and 0.25 Ω
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8 Ω and 2 Ω
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4 Ω and 1 Ω

Three identical resistors connected in series with a battery, together dissipate 10W of power. What will be the power dissipated, if the same resistors are connected in parallel across the same battery?

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60W
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30 W
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90 W
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120 W

A potentiometer wire of length 1 m and resistance 10Ω is connected in series with a cell of e.m.f 2V with internal resistance 1Ω and a resistance box of a resistance R if potential difference between ends of the wire is 1V the value of R is.

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4.5 Ω
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9 Ω
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15 Ω
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20 Ω

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 2Ω resistor and the balance is obtained across 40 cm of the wire, then the internal resistance of the cell is.

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1 Ω
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0.5 Ω
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1.2 Ω
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2.5 Ω

n idential cells each of e.m.f E and internal resistance r are connected in series An external resistance R is connected in series to this combination the current through R is.

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2)
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0%

4 cell each of emf 2v and internal resistance of 1Ω are connected in parallel to a load resistor of 2Ω Then the current through the load resistor is....

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2A
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1.5 A
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1A
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0.888A

A Potentiometer wire, 10m long, has a resistance of 40Ω It is connected in series with a resislance box and a 2V storage cell If the potential gradient along the wire is 0.1mv/cm, the resistance unplugged in the box is.

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260 Ω
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760 Ω
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960 Ω
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1060 Ω

Physics-Current Electricity II-66613.png

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2)
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Potentiometer wire of length 1m is connected in series with 490Ω resistance and 2V battery If 0.2 mv/ cm is the potential gradient, then resistance of the potentiometer wire is.

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4.9 Ω
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7.9 Ω
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5.9 Ω
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6.9 Ω

Physics-Current Electricity II-66620.png

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0%

Physics-Current Electricity II-66626.png

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2)
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The resistance of the series combination of two resistances is S, when they are joined in parallel the total resistance is P If S = n P, then the minimum possible value of n is....

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4
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3
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2
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1

Physics-Current Electricity II-66633.png

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In a wheatstone's bridge, three resistance P, Q and R connected in three are a and the fourth arm is formed by two resistances S₁ and S₂ connected in paralled The condition for bridge to be balanced will be

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Physics-Current Electricity II-66644.png

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3 Ω
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2
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1 Ω
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4 Ω

Resistors P and Q connected in the gaps of the meter bridge. the balancing point is obtained 1/3 m from the zero end If a 6Ω resistance is connected in series with p the balance point shifts to 2/3m form same end P and Q are

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4, 2
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2, 4
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both (a) and (b)
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neither (a) nor (b)

Physics-Current Electricity II-66646.png

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2)
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Two electric bulbs marked 25W-220V and 100W-220V are connected in series to a 440v supply which of the bulbs will fuse?

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100 W
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25 W
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None of these
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Both

2 A current is obtained when a 2Ω resistor is connectd with battery having rΩ as internal resistance 0.5A current is obtained if the above battery is connected to 9Ω resistor. Calculate the internal resistance of the battery.