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Two electric bulbs rated 25 W, 220 V and 100 W, 220 V are connected in series across a 220 V voltage source. The25 W and 100 W bulbs now draw P1 and P2 powers. Find P1 and P2.

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Important Questions on Current Electricity

HARD
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In the circuit shown, the resistance r is a variable resistance. If for r=fR , the heat generation in r is maximum then the value of f is
EASY
If the current through a resistor in a circuit increases by 3%, the power dissipated by the resistor
MEDIUM

A uniform metallic wire of length L is mounted in two configurations. In configuration 1 (triangle), it is an equilateral triangle and a voltage, V is applied to corners A and B. In configuration 2 (circle), it is bent in the form of a circle, and the potential V is applied at diametrically opposite points P and Q. The ratio of the power dissipated is configuration 1 to configuration 2 is.

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EASY
In which of the following devices, the eddy current effect is not used?
MEDIUM
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HARD
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HARD

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HARD

In the circuit shown, the heat produced in 5 Ω resistor is 10 cal s-1. The heat produced per sec in 4 Ω resistor will be

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MEDIUM
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HARD
The supply voltage to a room is 120 V. The resistance of the lead wires is 6  Ω . A 60 W bulb is already switched on. What is the decrease of voltage across the bulb, when a 240 W heater is switched on in parallel to the bulb?
MEDIUM
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EASY
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MEDIUM
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HARD
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Note: This question was awarded as the bonus since all options were incorrect in the exam. 
MEDIUM
In a building there are 15 bulbs of 45W , 15 bulbs of 100W,15 small fans of 10W and 2 heaters of 1kW . The voltage of electric main supply is 220V . The minimum fuse capacity (rated value) of the building will be:
MEDIUM

Consider the following two circuits

A : 20 bulbs are connected in series to a power supply line

B : 20 bulbs identical to A are connected in a parallel circuit to an identical power supply line

Identify which of the following is not true

EASY

ADC source with internal resistance R0 is connected to circuit as shown in the figure. The value of R for which the power generated in the circuit is the maximum is

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MEDIUM
A filament bulb (500 W, 100 V) is to be used in a 230 V main supply. When a resistance, R is connected in series, it works perfectly and the bulb consumes 500 W. The value of R is
EASY
The charge flowing through a resistance R varies with time t as Q=at-bt2 where a and b are positive constants. The total heat produced in R is: