Recent questions tagged 2013

Which one of the following statements is correct?

asked Oct 13, 2013 by thanvigandhi_1

1 answer

The emf of a cell E is 15 V as shown in the figure with an internal resistance of $ 0.5 \Omega $. Then the value of the current drawn from the cell is

asked Oct 13, 2013 by thanvigandhi_1

1 answer

When the temperature difference between the junctions of a given thermocouple is $120^{\circ}C$ , the thermo emf is 30 m V. The temperature of hot junction is decreased by $20^{\circ}C$ and cold junction is increased by $6^{\circ}C$ . The percentage decrease in thermo emf is ( assume thermo emf is directly proportional to the temperature difference)

asked Oct 13, 2013 by thanvigandhi_1

1 answer

A 0.01 H inductor and $ \sqrt 3\: \pi\: ohm$ resistance are connected in series with a 220 V, 50 Hz AC source. The phase difference between the current and emf is

asked Oct 12, 2013 by thanvigandhi_1

1 answer

An electron beam in a TV picture is accelerated through a potential difference of V volts. It passes through a region of transverse magnetic induction field (B) and follows a circular orbit of radius 'r'. The induced magnetic field (B) is

asked Oct 12, 2013 by thanvigandhi_1

1 answer

In moseley's law $ \sqrt v=a(z-b)$, the values of the screening constant for K-series and L-series of X-rays are respectively

asked Oct 12, 2013 by thanvigandhi_1

1 answer

The $ K_{ \alpha} - $ X-ray of molybdenum has a wave length of $ 71 \times 10^{-12}m$. If the energy of a molybdenum atom with K-electron removed is 23.32 KeV, then the energy of molybdenum atom when an L-electron removed is $(hc = 12.42 \times 10^{-7} eV)$

asked Oct 12, 2013 by thanvigandhi_1

1 answer

The purpose of using heavy water in nuclear reactor is

asked Oct 12, 2013 by thanvigandhi_1

1 answer

A $U^{235}$ reactor generates power at a rate of P producing $ 2 \times 10^{18}$ fissions per second. The energy released per fission is 185 MeV. The value of P is

asked Oct 12, 2013 by thanvigandhi_1

1 answer

A pnp transistor is used in common emitter mode in an amplifier circuit. When base current is changed by an amount $ \Delta I_B$, the collector current changes by 4 mA. If the current amplification factor is 60, then the value of $ \Delta I_B$ is

asked Oct 12, 2013 by thanvigandhi_1

1 answer

The necessary condition in making of a junction transistor ( E-emitter, B - base and C-collector)

asked Oct 12, 2013 by thanvigandhi_1

1 answer

The temperature at the two ends A and B of a rod of length 25 cm and circular cross section are $ 100^{\circ}C \: and \: 0^{\circ}C$ respectively. In the steady state the temperature at a point 10 cm from the end B is ( Ignore loss of heat from curved surface of the rod )

asked Oct 12, 2013 by thanvigandhi_1

1 answer

Two cylinders A and B fitted with pistons contain equal amount an ideal diatomic gas at 300 K. Piston of A is free to move and piston B is fixed. Same amount of heat is given to the gases in the two cylinders. Temperature of the gas in cylinder A increases by 30 K. Then, increase in temperature of the gas in the cylinder B is ( $ \gamma$ 1.4 for diatomic gas)

asked Oct 12, 2013 by thanvigandhi_1

1 answer

Match the following from table A, in the case of gases, with those in table B

asked Oct 12, 2013 by thanvigandhi_1

1 answer

A horizontal uniform tube, open at both ends is containing a liquid of certain length at some temperature. When the temperature is changed, the length of the liquid in the tube is not changed. If '$ \alpha$' is the coefficient of linear expansion of the material of the tube and '$ \gamma$' is the coefficient of volume expansion of the liquid, then

asked Oct 12, 2013 by thanvigandhi_1

1 answer

When a liquid is heated in a glass vessel, its coefficient of apparent expansion is $ 1.03 \times 10^{-3}/^{\circ}C$. When the same liquid is heated in a copper vessel, its coefficient of apparent expansion is $ 1.006 \times 10^{-3}/^{\circ}C$.If the coefficient of linear expansion of copper is $ 17 \times 10^{-6}/^{\circ}C$, then the coefficient of linear expansion of the glass is

asked Oct 10, 2013 by thanvigandhi_1

1 answer

Two capillary tubes of lengths in the ratio 2 : 1 and radii in the ratio 1 : 2 are connected in series. Assume the flow of the liquid through the tube is steady. Then, the ratio of pressure difference accros the tubes is

asked Oct 10, 2013 by thanvigandhi_1

1 answer

Water rises in a capillary tube upto a height of 10 cm whereas mercury depresses in it by 3.42 cm. If the angle of contact and density of mercury are $ 135^{\circ}$ and 13.6 gm/cc respectively, then the ratio of the surface tension of water and mercury will be nearly

asked Oct 10, 2013 by thanvigandhi_1

1 answer

Force constants of two wires A and B of the same material are K and 2K respectively. If the two wires are stretched equally , then the ratio of work done in stretching $ \bigg( \large\frac{W_A}{W_B} \bigg)$ is

asked Oct 10, 2013 by thanvigandhi_1

1 answer

A particle is executing simple harmonic motion along a straight line. At displacements $r_1 \: and r_2$ from its mean position the velocities are $v_1 \: and \: v_2$ . The time period of the particle is

asked Oct 10, 2013 by thanvigandhi_1

1 answer