Recent questions tagged ch5

For what value of $R$ will the current passing through the $4\: ohm$ resistor is zero

asked Feb 10, 2014 by thanvigandhi_1

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The resistor which will dissipate maximum power is

asked Feb 10, 2014 by thanvigandhi_1

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In the circuit shown, if a wire is connected between points A and B, how much current will flow through it?

asked Feb 10, 2014 by thanvigandhi_1

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Find the equivalent resistance between A and B

asked Feb 10, 2014 by thanvigandhi_1

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Current passing through the $1\: ohm$ resistor is zero. The value of $ E$ is

asked Feb 10, 2014 by thanvigandhi_1

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An ammeter and a voltmeter are joined in series to a battery. Their readings are $A$ and $V$ respectively. If a resistance is now joined in parallel with the voltmeter

asked Feb 10, 2014 by thanvigandhi_1

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Which of these is correct for each pair of statements? \[\] Statement 1: $40W$ tube light appears brighter than a $40W$ bulb.\[\] Statement2: Light sources having same power rating appear to glow equally brightly

asked Feb 10, 2014 by thanvigandhi_1

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Which of these is correct for each pair of statements? \[\] Statement 1: Resistance of $50W$ bulb is greater than that of a $100W$ bulb. \[\] Statement 2: Resistance of a bulb is inversely proportional to rated power.

asked Feb 10, 2014 by thanvigandhi_1

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Which of these is correct for each pair of statements? \[\] Statement 1: The conductivity of molten electrolytes is smaller than common metallic conductors. \[\] Statement 2: Positive and negative ions flow in opposite directions.

asked Feb 10, 2014 by thanvigandhi_1

1 answer

Which of these is correct for each pair of statements? \[\] Statement 1: When a battery is short-circuited, the terminal voltage is zero \[\] Statement 2: In the situation of a short-circuit, the current is zero

asked Feb 10, 2014 by thanvigandhi_1

1 answer

Which of these is correct for each pair of statements? \[\] Statement 1: When an electric current at the junction of two wires of the same material is directed from the thick wire to the thin wire, the drift speed of the electrons increase as they pass through the cross-section \[\] Statement 2: The drift speed of electrons is directly proportional to the electric field in the wire.

asked Feb 10, 2014 by thanvigandhi_1

1 answer

A wire of resistance $10\Omega$ is bent to form a circle. $P$ and $Q$ are two points on it such that the arc $PQ$ subtends a right angle at the center. A $3V$ battery having internal resistance of $ 1\Omega$ is connected across $P$ and Q, the currents in the two parts of the circle are

asked Feb 10, 2014 by thanvigandhi_1

1 answer

Three resistances $ R, 2R$ and $3R$ are connected in parallel to a battery. Then

asked Feb 10, 2014 by thanvigandhi_1

1 answer

In a Hydrogen atom, an electron moves in an orbit of radius $5 \times 10^{-11}m$ with a speed of $2.2 \times 10^6 m/s.$ Calculate the equivalent current.

asked Feb 10, 2014 by thanvigandhi_1

1 answer

To get maximum current through a resistance of $2.5\Omega$, one can use $‘m’ $ rows of cells, each containing $‘n’$ cells connected in series. The internal resistance of each cell is $0.5\Omega$. What are the values of $ n$ and $m$ if the total numbers of cells are $45$?

asked Feb 10, 2014 by thanvigandhi_1

1 answer

A battery of internal resistance $2 \Omega$ is connected to a variable resistor whose value can be varied from $ 4\Omega\: to\: 10\Omega$. If the variable resistance is gradually increased from an initial value of $4\Omega$, the power consumed by it:

asked Feb 10, 2014 by thanvigandhi_1

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How many electrons flow through the filament of a $120V, 60W $ bulb in one second?

asked Feb 10, 2014 by thanvigandhi_1

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A current of $1A $ is passing through $ CuSO_4 $ solution. How many $Cu^{+2}ions$ ions will be deposited at the cathode in 5 seconds?

asked Feb 10, 2014 by thanvigandhi_1

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A uniform wire has resistance $R$. It is cut into n equal parts and all of them are connected in parallel to each other. The resistance of the combination is:

asked Feb 10, 2014 by thanvigandhi_1

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A battery is supplying power to a tape-recorder by cable of resistance $0.02\Omega$. If the battery is generating $50W $ at $5V$, the power received by the tape-recorder is:

asked Feb 10, 2014 by thanvigandhi_1

1 answer

Calculate the mean free path in $Cu$ at room temperature $300K$, if the number density of free electrons is $8.5 \times 10^{28}/m^3$ and resistivity $r = 1.7 \times 10^{-8} mho-m$. Given $k = 1.38 \times 10^{-23} J/K \: and\: 1A = 10^{-10} m$

asked Feb 10, 2014 by thanvigandhi_1

1 answer

This question has statement I and statement II. Of the four choices given after the statements, choose the one that best describes the two statements.\[\] Statement- I: In a meter bridge experiment, the null point for the unknown resistance is measured. Now, the resistance is put inside an enclosure maintained at a higher temperature. The null point can be obtained at the same point as before by decreasing the value of the standard resistance. \[\] Statement- II: Resistance of a metal increases with temperature.

asked Feb 10, 2014 by thanvigandhi_1

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A constant voltage is applied to the two ends of a uniform metallic wire. Some heat is produced in it. The heat developed is doubled if

asked Feb 8, 2014 by thanvigandhi_1

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This question has statement I and statement II. Of the four choices given after the statements, choose the one that best describes the two statements. \[\] Statement- I: Electrons in a conductor have no motion in the absence of a potential difference across it. \[\] Statement- II: The electric field inside the static conductor is always zero.

asked Feb 8, 2014 by thanvigandhi_1

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Find the resistance of the wire frame shaped as a cube when measured between the points 1 and 3. The resistance of each edge is R

asked Feb 8, 2014 by thanvigandhi_1

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Find the resistance of the wire frame shaped as a cube when measured between the points 1 and 2. The resistance of each edge is R

asked Feb 8, 2014 by thanvigandhi_1

1 answer

Find the resistance of the wire frame shaped as a cube when measured between the points 1 and 7. The resistance of each edge is R

asked Feb 8, 2014 by thanvigandhi_1

1 answer

Two capacitors $C_1$ and $C_2$ are charged to $120\: V$ and $ 200\: V$ respectively. It is found that by connecting them together the potential on each one can be made zero. Then:

asked Feb 8, 2014 by thanvigandhi_1

1 answer

This question has statement I and statement II. Of the four choices given after the statements, choose the one that best describes the two statements. \[\] Statement- I: Higher the range, greater is the resistance of ammeter. \[\] Statement- II: To increase the range of ammeter, additional shunt needs to be used across it.

asked Feb 8, 2014 by thanvigandhi_1

1 answer

The supply voltage to a room is $120\: V\: DC$. The resistance of the lead wires is $6 \Omega$. 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?

asked Feb 8, 2014 by thanvigandhi_1

1 answer

Resistance of a given wire is obtained by measuring the current flowing in it and the voltage difference applied across it. If the percentage errors in the measurement of the current and the voltage difference are 3% each, then error in the value of resistance of the wire is

asked Feb 8, 2014 by thanvigandhi_1

1 answer

Two electric bulbs marked $25W – 220V$ and $100W – 220V$ are connected in series to a $440V$ supply. Which of the bulbs will fuse?

asked Feb 8, 2014 by thanvigandhi_1

1 answer

A resistance of $2 \Omega$ is connected across one gap of a meter-bridge and an unknown resistance, greater than $2 \Omega$, is connected across the other gap. When these resistances are interchanged, the balance point shifts by $20cm$. The unknown resistance is

asked Feb 8, 2014 by thanvigandhi_1

1 answer

A moving coil galvanometer of resistance $100 \Omega$ is used as an ammeter using a resistance of $ 0.1 \Omega$. The maximum deflection current in the galvanometer is $100 \mu A$. Find the current in the circuit so that the ammeter shows full scale deflection

asked Feb 8, 2014 by thanvigandhi_1

1 answer

A rigid container with thermally insulated walls contains a coil of $100 \Omega$ resistance with a current of $1A$. Change in internal energy after 5 min will be

asked Feb 8, 2014 by thanvigandhi_1

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A steady current flows in a metallic conductor of non-uniform cross-section. The quantity/quantities constant along the length of the conductor are

asked Feb 8, 2014 by thanvigandhi_1

1 answer

If $ \sqrt{1-y^2}-\sqrt{1-x^2}=a(x-y),\normalsize$ then find $\large\frac{dy}{dx}$

asked Feb 5, 2014 by rvidyagovindarajan_1

1 answer

If $e^{x+y}=xy,$ what is $\large\frac{dy}{dx}$?

asked Jan 29, 2014 by balaji

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The set of points where the function $f(x)=\sqrt{1-e^{-x^2}}$ is differentiable is

asked Jan 6, 2014 by sreemathi.v

1 answer

At the point $x=1$ the function $f(x)=\left\{\begin{array}{1 1}x^3-1&1 < x < \infty\\x-1&-\infty < x \leq 1\end{array}\right.$ is

asked Jan 6, 2014 by sreemathi.v

1 answer

$f(x)=\left\{\begin{array}{1 1}\large\frac{1-\cos 4x}{x^2}&x < 0\\a&x=0\\\large\frac{\sqrt x}{\sqrt{[16+\sqrt x]-4}}&x > 0\end{array}\right.$If the function be continuous at $x=0$ then $a=$

asked Jan 6, 2014 by sreemathi.v

1 answer

The function $f(x)=\left\{\begin{array}{1 1}x+a\sqrt 2\sin x&0\leq x < \large\frac{\pi}{4}\\2x\cot x+b&\large\frac{\pi}{4}\normalsize \leq x < \frac{\pi}{2}\\a\cos 2x-b\sin x&\large\frac{\pi}{2}\normalsize < x \leq \pi\end{array}\right.$ is continuous for $0 \leq x \leq \pi$ then a,b are

asked Jan 6, 2014 by sreemathi.v

1 answer

The function $f(x)=\left\{\begin{array}{1 1}\large\frac{x^2}{a}&0\leq x <1\\a&1\leq x < \sqrt 2\\\large\frac{2b^2-4b}{x^2}&\sqrt 2\leq x < \infty\end{array}\right.$ is continuous for $0\leq x < \infty$ then the most suitable values of a and b are

asked Jan 4, 2014 by sreemathi.v

1 answer

The value of $\lim\limits_{x\to 0}\large\frac{\sqrt{\Large\frac{1}{2}\normalsize (1-\cos 2x)}}{x}$

asked Jan 4, 2014 by sreemathi.v

1 answer

If $f(x)=\large\frac{x}{2}$$-1$, then on the interval $[0,\pi]$

asked Jan 4, 2014 by sreemathi.v

1 answer

The set of all points where the function $f(x)=\large\frac{x}{(1+|x|)}$ is differentiable is

asked Jan 4, 2014 by sreemathi.v

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Let $[x]$ denote the greatest integer less than or equal to x. If $f(x)=[x\sin\pi x]$, then $f(x)$ is

asked Jan 3, 2014 by sreemathi.v

1 answer

If $f(x)=x(\sqrt{x}-\sqrt{x+1})$ then

asked Jan 3, 2014 by sreemathi.v

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If $x+|y|=2y$, then $y$ as a function of x is

asked Jan 3, 2014 by sreemathi.v

1 answer

Consider the function $f(x)=|x-2|+|x-5|\;x\in R$.

asked Jan 3, 2014 by sreemathi.v

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