Recent questions tagged sec-b

A magnetic field of 10T acts normal to a coil of 50 turns having $100 cm^2$ area. Find emf induced if the coil is removed from magnetic field in 0.1 sec.

asked Dec 30, 2016 by suganyadevi.p

1 answer

A wheel with 50 metallic spokes each 0.5 m long is rotated with an angular speed of 12 radian /sec, in a plane normal to the earth's magnetic field. If the magnitude of the field is $ 0.5 \times 10^{-4}$ T, calculate the emf induced between the axle and the rim of the wheel.

asked Dec 30, 2016 by suganyadevi.p

1 answer

For a common emitter amplifier , the audio signal voltage across the collector resistance of $2\;HK \Omega$ is $2V$. Suppose the current amplification factor of a transistor is 100, find the input signal voltage and base current , if the base resistance is $1\;k \;\Omega$

asked Dec 30, 2016 by meena.p

1 answer

A circular coil of radius 8.0 cm and 20 turns rotates about its vertical diameter with an angular speed of $ 50 rad s^{-1}$ in a uniform horizontal magnetic field of magnitude $ 3 \times 10^{-2} T$. It the coil forms a closed loop of resistance $ 10 \Omega$, calculate the power dissipated as heat.

asked Dec 30, 2016 by suganyadevi.p

1 answer

A circular coil of radius 8.0 cm and 20 turns rotates about its vertical diameter with an angular speed of 50 $rad s^{-1}$ in a uniform horizontal magnetic field of magnitude $ 3 \times 10^{-2} T$. Calculate the maximum emf induced in the coil.

asked Dec 30, 2016 by suganyadevi.p

1 answer

A magnetic field of flux density $1.0 wb m^{-2}$ acts normal to a 80 turn coil of 0.01 m^2 area. Find the e.m.f induced in it, if this coil is removed from the field in 0.1 second.

asked Dec 30, 2016 by suganyadevi.p

1 answer

Current in a circuit falls from $5.0 A$ to $0.0 A$ in $0.1 S$. If an average $emf$ of $ 200 V$ induced, given an estimate of the self-inductance of the circuit.

asked Dec 30, 2016 by priyanka.c

1 answer

A conducting wire of 100 turns is wound over 1cm near the centre of a solenoid of 100 cm length and 2 cm radius having 1000 turns. Calculate the coefficient of mutual inductance of the two solenoids.

asked Dec 30, 2016 by suganyadevi.p

1 answer

A solenoid coil has 50 turns per cm along its length and a cross sectional area of $4cm^2$, 200 turns of another wire are wound round the first solenoid co-axially. The two coils are electrically insulated from each other. Calculate the mutual inductance between the two coils.

asked Dec 30, 2016 by suganyadevi.p

1 answer

An e.m.f of 250 microvolt in induced in a coil when current in it changes from 10A to 6A in 0.4 second. What is the self inductance of the coil?

asked Dec 30, 2016 by suganyadevi.p

1 answer

As soon as current is switched on a high voltage line, the bird sitting on it flies away. Why??

asked Dec 30, 2016 by suganyadevi.p

1 answer

The magnetic flex through a coil perpendicular to its plane and directed into paper is varying according to the relation $\phi = (5t^2 + 10t + 5)$ milliwebers. Calculate the e.m.f induced in the loop.

asked Dec 30, 2016 by suganyadevi.p

1 answer

An aircraft with a wingspan of 40m flies with a speed of 1080 $km hr^{-1}$ in the eastward direction at a constant altitude in the northern hemisphere where the vertical component of earth's magnetic field is $1.75 \times 10^{-5} T$. Find the emf that develops between the tips of the wings.

asked Dec 30, 2016 by suganyadevi.p

1 answer

A 12v battery connected to a $6 \Omega$, 10H coil through a switch drives a constant current in the circuit. Th switch is suddenly opened. Assuming that it took 1 millisecond to open the switch. Calculate the average e.m.f induced across the coil.

asked Dec 30, 2016 by suganyadevi.p

1 answer

A $1.0m $ long metallic rod is rotated with an angular frequency of $400 rad/s$ about an axis normal to the rod passing through its one end. The other end of the rod is in contact with a circular metallic ring. A constant and uniform magnetic field of $0.5 \;T$ parallel to the axis exists everywhere. Calculate the $emf$ developed between the centre and the ring.

asked Dec 29, 2016 by priyanka.c

1 answer

A rectangular wire loop of slides $8 \;cm$ and $2\;cm$ with a small cut is moving out of a region of uniform field of magnitude $0.3T$ directed normal to the loop. What is the $emf$ developed across the cut if the velocity of the loop is $1\;cm/s$ in a direction normal to the shorter side of the loop. For how long does induced voltage last in each case.

asked Dec 29, 2016 by priyanka.c

1 answer

A long solenoid with $15\; turns\; per\; cm $ has a small loop of area $2.0cm^2$ placed inside the solenoid normal to its axis. If the current carried by the solenoid changes steadily from $2.0 A \; to \;4.0 A $ in $0.1 S ,$ what is the induced $emf$ in the loop while the current is changing?

asked Dec 29, 2016 by priyanka.c

1 answer

There are two coils A and B separated by some distance. If a current of 2A flows through A, a magnetic flex of $10^{-2}$ wb passes through B (no current through B). If no current passes through A and a current of 1A passes through B, what is the flex through A?

asked Dec 29, 2016 by suganyadevi.p

1 answer

Find the current in the wine PQ for the configuration as shown in the fig. Wire PQ has negligible resistance. B, the magnetic field is coming out of the paper. $\theta$ is a fixed angle made by PQ travelling smoothly over two conducting parallel wires separated by a distance d.

asked Dec 29, 2016 by suganyadevi.p

1 answer

(i) In a cell reaction, the equilibrium constant K is less than one. Is E° for the cell positive or negative ? (ii) What will be the value of K of $E^{\circ}$ cell = 0 ?

asked Dec 29, 2016 by sharmaaparna1

1 answer

Out of (a) 200 ml of 2 M NaCl Soln and (b) 200 ml of 1 M glucose Soln. which one has higher osmotic pressure ?

asked Dec 29, 2016 by sharmaaparna1

1 answer

Why are coral reefs not found in the regions of West Bengal to Andhra Pradesh but are found in Tamil nadu and on the east coast of India?

asked Dec 27, 2016 by meena.p

1 answer

How does Monascus help in controlling blood cholesterol?

asked Dec 27, 2016 by meena.p

1 answer

asked Dec 27, 2016 by meena.p

1 answer

How is the child affected if it is grown from the zygote formed by an XX egg fertilized by a Y carrying sperm? What do you call this abnormality?

asked Dec 27, 2016 by meena.p

1 answer

How does Cu-T act as a contraceptive?Give the function of corpus luteum and endometrium.

asked Dec 27, 2016 by meena.p

1 answer

What are sacred groves? What is their role in conservation?

asked Dec 26, 2016 by meena.p

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What are methanogens? Give an example.

asked Dec 26, 2016 by meena.p

1 answer

What is artificial insemination? What are the advantages of this technique?

asked Dec 26, 2016 by meena.p

1 answer

Would you consider wings of butterfly and bat homologus or analogus? Why?The process of termination during transcription in a prokaryotic cell is being represented here. Name the labeled parts a,b,c and d.

asked Dec 26, 2016 by meena.p

1 answer

What is the number of chromosomes in the following cells? Primary oocyte, Secondary oocyte, Ootid and follicle.

asked Dec 26, 2016 by meena.p

1 answer

Differentiate between primary productivity and secondary productivity.

asked Dec 21, 2016 by meena.p

1 answer

A farmer adds Azatobacter to the soil before sowing maize. How does it increase the yield of the maize?

asked Dec 21, 2016 by meena.p

1 answer

What is inbreeding depression? Why do self pollinated crops show the effects of inbreeding depression?

asked Dec 21, 2016 by meena.p

1 answer

Why has natural selection not eliminated sickle cell anemia?

asked Dec 21, 2016 by meena.p

1 answer

What does GIFT represent? Bryophytes and pteridophytes produce a large number of male gametes but relatively a few female gametes. Why?

asked Dec 21, 2016 by meena.p

1 answer

Find the value of $x, y, z $ if the matrix. $\begin{bmatrix} 0 & 2y & z \\ x & y & -z \\ x & -y & z \end{bmatrix}$ satisfy the equation $A^TA =I_3$

asked Dec 21, 2016 by priyanka.c

1 answer

Using differentials, find the appropriate value of $[0.009] ^ {\frac{1}{3}}$

asked Dec 20, 2016 by priyanka.c

1 answer

If $\overrightarrow {b} \times \overrightarrow {c} = \overrightarrow {c} \overrightarrow {a} \neq 0$, then $\overrightarrow{a} + \overrightarrow {b} = k \overrightarrow {c}$ where k is any scalar.
Is it true or false .

asked Dec 20, 2016 by priyanka.c

1 answer

A die is thrown 10 times. If getting a prime number is considered a success, find the probability of getting not more than 8 successes.

asked Dec 20, 2016 by priyanka.c

1 answer

From the differential equation of the family of curves $y = A \sin 2x + B \cos 2x$

asked Dec 20, 2016 by priyanka.c

1 answer

If $f'(x) = 6x^2+2,$ find $f(x)$, given that $f(x) = 7$ when $x=1$

asked Dec 20, 2016 by priyanka.c

1 answer

If $y = 7x -x^3$ and $x$ increases at the rate of 4 units per second. How fast is the slope of the curve changing when $x=2$

asked Dec 20, 2016 by priyanka.c

1 answer

What is photochemical smog composed of? How does it affect plants?

asked Dec 20, 2016 by meena.p

1 answer

Why do bottled juices appear clearer than homemade ones?

asked Dec 20, 2016 by meena.p

1 answer

What is metastasis? or Where are T-cells and B-cells formed? How do they differ from each other?

asked Dec 20, 2016 by meena.p

1 answer

What is frame shift mutation? Name any one disease caused due to this mutation?

asked Dec 20, 2016 by meena.p

1 answer

Draw a neat labeled diagram of a human sperm.

asked Dec 20, 2016 by meena.p

1 answer

If $A =\begin{bmatrix} x & -2 \\ 3 & 7 \end{bmatrix}$ and $A^{-1} = \begin{bmatrix} \frac{7}{34} & \frac{1}{17} \\ \frac{3}{34} & \frac{2}{17} \end{bmatrix}$ then find the value of $x $.

asked Dec 20, 2016 by priyanka.c

1 answer

What is brood parasitism? Give an example

asked Dec 19, 2016 by meena.p

1 answer

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