The rms speed (in m/s) of oxygen molecules of the gas at temperature \(300\) K, is:
1. \(483\)
2. \(504\)
3. \(377\)
4. \(346\)

Subtopic:  Types of Velocities |
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A horizontal tube of length \(l\) dosed at both ends contains an ideal gas of molecular weight \(M.\) The tube is rotated at a constant angular velocity \(\omega\) about a vertical axis passing through an end. Assuming the temperature to be uniform and constant. If \(P_1\) and \(P_2\) denote the pressure at the free and the fixed end respectively, then choose the correct relation.
1. \(\frac{P_2}{P_1}=e^{\frac{M\omega^2l^2}{2RT}}\)
2. \(\frac{P_1}{P_2}=e^{\frac{M\omega^2}{RT}}\)
3. \(\frac{P_1}{P_2}=e^{\frac{\omega lM}{3RT}}\)
4. \(\frac{P_2}{P_1}=e^{\frac{M^2\omega^2l^2}{3RT}}\)

Subtopic:  Ideal Gas Equation |
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The parts of two concentric circular arcs joined by two radial lines and carries current \(i.\) The arcs subtend an angle \(\theta\) at the centre of the circle the magnetic field at the centre \(O,\) is:
1. \(\frac{\mu_{_0}i(b-a)\theta}{4\pi ab}\)
2. \(\frac{\mu_{_0}i(b-a)}{4\pi ab}\)
3. \(\frac{\mu_{_0}i(b-a)\theta}{\pi ab}\)
4. \(\frac{\mu_{_0}i(a-b)}{2\pi ab}\)

Subtopic:  Magnetic Field due to various cases |
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\(1\) kg of water is converted into steam at the same temperature and at \(1\) atm (\(100\) kPa). The density of water and steam are \(1000\) kgm-3 and \(0.6\) kgm-3 respectively. The latent heat of vaporization of water is \(2.25 \times 10^6 \mathrm{~J} \mathrm{~kg}^{-1}\). What will be the increase in energy?
1. \( 3 \times 10^5 \mathrm{~J} \)
2. \( 4 \times 10^6 \mathrm{~J} \)
3. \( 2.08 \times 10^6 \mathrm{~J}\) 
4.  None of these
Subtopic:  Calorimetry |
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The ammeter shown in figure consists of a 480 \(\Omega\) coil connected in parallel to a 20 \(\Omega\) shunt. The reading of the  ammeter is:
           

1. 0.125 A
2. 1.67 A
3. 0.13 A
4. 0.67A

Subtopic:  Combination of Resistors |
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A lead ball at 30°C is dropped from a height of 6.2 km. The ball is heated due to the air resistance and it completely melts just before reaching the ground. The molten substance falls slowly on the ground. If the specific heat of lead = 126 Jkg-1oc-1 and a melting point of lead = 330°C and suppose that any mechanical energy lost is used to heat the ball, then the latent heat of fusion of lead is:
1.  2.4 × 104 J kg-1
2.  3.6 × 104 J kg-1
3.  7.6 × 102 J kg-1
4.  42 × 103 J kg-1
Subtopic:  Calorimetry |
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An inductor (L = 20 H), a resistor (R = 100 \(\Omega\)) and a battery (E = 10 V) are connected in series. After a long time, the circuit is short-circuited and then the battery is disconnected. Find the current in the circuit at 1 ms after short-circuiting.

1.  4.5 x 106 A
2.  3.2 x 10-5 A
3.  9.8 x 10-6 A
4.  6.7 x 10-4 A

Subtopic:  Different Types of AC Circuits |
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Two charges of + 10 \(\mu\text C\) and +20 \(\mu\text C\) are separated by a distance of 2 cm. The net potential (electric) due to the pair at the middle point of the line joining the two changes, is:

1.  27 MV
2.  18 MV
3.  20 MV
4.  23 MV

Subtopic:  Electric Potential |
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A copper rod of length 20 cm and cross-sectional area 2 mm2 is joined with a similar aluminium rod as shown below,

The resistance of a pair of rods is:
( and  \((\rho_{_{al}}=2.6\times10^{-6})~\Omega-m\) and \((\rho_{_{Cu}}=1.7\times10^{-8})~\Omega-m\)

1.  1.0 m\(\Omega\)
2.  2.0 m\(\Omega\)
3.  3.0 m\(\Omega\)
4.  None of these

Subtopic:  Combination of Resistors |
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A particle is subjected to two simple harmonic motions along the X-axis while the other is along a line making an angle of 45° with the X-axis. The two motions are given by \(x = x_0\) sin \(\omega t\) and \(s = s_0\) sin \(\omega t\). The amplitude of the resultant motion is:
1. \(x_0+s_0+2x_0s_0\)
2. \(\sqrt{x^2_0+s^2_0}\)
3. \(\sqrt{x^2_0+s^2_0+2x_0s_0}\)
4. \(x^2_0=s^2_0+\sqrt2x_0s_0~^{1/2}\)

Subtopic:  Simple Harmonic Motion |
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