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Aparna Sahu
Subject: Physics
, asked on 19/5/18
$Alongoverheadtransmissionlineis5.0mabovethegroundandcarriesadirectcurrent120A.Themagneticindcutionatapointdirectlybelowthelinewillbe\phantom{\rule{0ex}{0ex}}\left(a\right)2.4\times {10}^{-7}Tperpendiculartowire\phantom{\rule{0ex}{0ex}}\left(b\right)4.8\times {10}^{-6}Tperpendiculartowire\phantom{\rule{0ex}{0ex}}\left(c\right)2.4\times {10}^{-7}Talongthewire\phantom{\rule{0ex}{0ex}}\left(d\right)4.8\times {10}^{-6}Talongthewire$
Answer
1
Bhavya Jain
Subject: Physics
, asked on 16/5/18
Why/How will the ring expand in the following case? Give reasoning
Q.26. A conducting loop carrying a current I is placed in xy-plane. A uniform magnetic field pointing into Z-direction is switched on. The loop will have a tendency to
a. contract
b. expand
c. move towards + ve X-axis
d. move towards - ve X-axis
Answer
1
Jeneeta Eliza John
Subject: Physics
, asked on 1/5/18
Explain question no.40. Ans is(1):
40. Figure shows a circular wheel of radius 10.0 cm whose upper half is made of iron and lower half of wood. The two junctions are joined by an iron rod. Uniform magnetic field B of magnitude 2x10
^{-4}
T exists in space as shown. The wheel is set in pure rolling. If it takes 2.0 s for the iron part to come down and wooden part to go up then average induced emf during this period is.
(1) 1.57 x 10
^{-6}
V (2) 1.5 x 10
^{-7}
V
(3) 15.7 x 10
^{-6}
V (4) 1.55 x 10
^{-8}
V
Answer
0
Jeneeta Eliza John
Subject: Physics
, asked on 1/5/18
Explain no.37. Ans is(4)
$Arec\mathrm{tan}gularcoilof\mathrm{sin}gleturn,havingareaA,rotatesinauniformmagneticfieldBwithangularspeed\omega aboutanaxisperpendiculartothefield.Ifinitiallytheplaneofthecoilisperpendiculartothefield,thentheaverageinducedemfwhenithasrotatedthrough90\xb0is\phantom{\rule{0ex}{0ex}}\left(1\right)\frac{\omega BA}{\pi}\phantom{\rule{0ex}{0ex}}\left(2\right)\frac{\omega BA}{2\pi}\phantom{\rule{0ex}{0ex}}\left(3\right)\frac{\omega BA}{4\pi}\phantom{\rule{0ex}{0ex}}\left(4\right)\frac{2\omega BA}{\pi}$
Answer
1
Lavneesh Rajput
Subject: Physics
, asked on 25/4/18
please derive this equation
Q.
$F=-\frac{\u2206U}{\u2206x}$
Answer
1
Aparna Sahu
Subject: Physics
, asked on 24/4/18
Solve this :
11. An iron rod of length 100 cm and 10 cm
^{2}
cross-section is heated from 0
^{o}
C to 100
^{o}
If it is not allowed to bend or expand, what force is developed in it ? Given that Y -10
^{12}
dyne/cm
^{2}
and a = 10
^{-5}
/
^{o}
C.
(a) 10
^{8}
dyne
(b) 10
^{9}
dyne
(c) 10
^{10}
dyne
(d) 10
^{11}
dyne
Answer
1
Aparna Sahu
Subject: Physics
, asked on 23/4/18
Solve this:
Q.16. If the terminal speed of a sphere of gold [density = 19.5 g/
$c{m}^{3}$
] is 0.2 m/s in a viscous liquid [density = 1.5 g/
$c{m}^{3}$
], find the terminal speed of a sphere of silver [density = 10.5 g/
$c{m}^{3}$
] of the same size in the same liquid.
(a) 0.133 m/s
(b) 0.1 m/s
(c) 0.2 m/s
(d) 0.4 m/s
Answer
2
Jeneeta Eliza John
Subject: Physics
, asked on 21/4/18
The ans given is four times, but if we increase the number of turns by two times without change in length of the solenoid, shouldn't the radius also decrease by 2 times? Hence, won't the self inductance become eight times?:
26. When the number of turns in a solenoid are doubled without any change in the length of the solenoid, it self inductance becomes.
(1) Half (2) Double (3) Four Times (4) Eight times.
Answer
2
Jeneeta Eliza John
Subject: Physics
, asked on 21/4/18
A copper rod of length l is rotating about mid point perpendicular to the magnetic field B with constant angular velocity omega the induces emf between the two ends is?....Ans is zero, please explain why
Answer
1
Muhammad Arafath R Z
Subject: Physics
, asked on 18/4/18
Pls answer this Carnot engine mains question
Q 5. Two Carnot engines A and B are operated in series. Engine A receives heat from a reservoir at 600 K and rejects heat to a reservoir at temperature T. Engine B receives heat rejected by engine A and in turn rejects it to a reservoir at 100 K. If the efficiencies of the two engines A and B are represent
ed by
$\eta $
_{A }
and
$\eta $
_{B}
, respectively, then what is the value of
$\frac{{\eta}_{B}}{{\eta}_{A}}?$
Option :
$1.\frac{7}{12}\phantom{\rule{0ex}{0ex}}2.\frac{12}{5}\phantom{\rule{0ex}{0ex}}3.\frac{12}{7}\phantom{\rule{0ex}{0ex}}4.\frac{5}{12}$
Answer
1
Laieeqa
Subject: Physics
, asked on 17/4/18
Ques.
A solenoid of inductance 2H carries a current of 1 A. What is the magnetic energy stored in a solenoid ?
(1) 2 J (2) 1 J
(3) 4 J (4) 5
Answer
1
Palak
Subject: Physics
, asked on 16/4/18
Pls explain this question:
Illustration 5.
Five point charges, each of value +q are placed of five vertices of a regular hexagon of side L. What is the magnitude of the force on a point charge of value-q placed at the centre of the hexagon ?
Answer
1
Aparna Sahu
Subject: Physics
, asked on 16/4/18
41. When a wave passes from one medium to another, there is change in
(a) frequency and velocity
(b) frequency and wavelength
(c) wavelength and velocity
(d) frequency, wavelength and velocity
42. A fork gives 5 beats with a 40 cm length of sonometre wire. If the length ofthe wire is shortened by 1 cm, the number of beats is still the same. The frequency of the fork is
(a) 385 Hz
(b) 600 Hz
(c) 395 Hz
(d) 400 Hz
Answer
3
Aparna Sahu
Subject: Physics
, asked on 12/4/18
Solve qus no. 38
Q38. The heart beat of a person is 90 per minute. The frequency is
(a) 90 Hz (b) 60 Hz
(c) 1.33 Hz (d) 1.5 Hz
Answer
1
Annabeth Chase
Subject: Physics
, asked on 10/4/18
Q. Find the EMF induced in metal loop when it moves in non-uniform magnetic field
Answer
1
1
2
3
4
5
Next
What are you looking for?

Q.26. A conducting loop carrying a current I is placed in xy-plane. A uniform magnetic field pointing into Z-direction is switched on. The loop will have a tendency to

a. contract

b. expand

c. move towards + ve X-axis

d. move towards - ve X-axis

40. Figure shows a circular wheel of radius 10.0 cm whose upper half is made of iron and lower half of wood. The two junctions are joined by an iron rod. Uniform magnetic field B of magnitude 2x10

^{-4}T exists in space as shown. The wheel is set in pure rolling. If it takes 2.0 s for the iron part to come down and wooden part to go up then average induced emf during this period is.(1) 1.57 x 10

^{-6}V (2) 1.5 x 10^{-7}V(3) 15.7 x 10

^{-6}V (4) 1.55 x 10^{-8}V$Arec\mathrm{tan}gularcoilof\mathrm{sin}gleturn,havingareaA,rotatesinauniformmagneticfieldBwithangularspeed\omega aboutanaxisperpendiculartothefield.Ifinitiallytheplaneofthecoilisperpendiculartothefield,thentheaverageinducedemfwhenithasrotatedthrough90\xb0is\phantom{\rule{0ex}{0ex}}\left(1\right)\frac{\omega BA}{\pi}\phantom{\rule{0ex}{0ex}}\left(2\right)\frac{\omega BA}{2\pi}\phantom{\rule{0ex}{0ex}}\left(3\right)\frac{\omega BA}{4\pi}\phantom{\rule{0ex}{0ex}}\left(4\right)\frac{2\omega BA}{\pi}$

Q. $F=-\frac{\u2206U}{\u2206x}$

Solve this :11. An iron rod of length 100 cm and 10 cm

^{2}cross-section is heated from 0^{o}C to 100^{o}If it is not allowed to bend or expand, what force is developed in it ? Given that Y -10^{12}dyne/cm^{2}and a = 10^{-5}/^{o}C.(a) 10

^{8}dyne(b) 10

^{9}dyne(c) 10

^{10}dyne(d) 10

^{11}dyneQ.16. If the terminal speed of a sphere of gold [density = 19.5 g/$c{m}^{3}$] is 0.2 m/s in a viscous liquid [density = 1.5 g/$c{m}^{3}$], find the terminal speed of a sphere of silver [density = 10.5 g/$c{m}^{3}$] of the same size in the same liquid.

(a) 0.133 m/s

(b) 0.1 m/s

(c) 0.2 m/s

(d) 0.4 m/s

26. When the number of turns in a solenoid are doubled without any change in the length of the solenoid, it self inductance becomes.

(1) Half (2) Double (3) Four Times (4) Eight times.

Q 5. Two Carnot engines A and B are operated in series. Engine A receives heat from a reservoir at 600 K and rejects heat to a reservoir at temperature T. Engine B receives heat rejected by engine A and in turn rejects it to a reservoir at 100 K. If the efficiencies of the two engines A and B are represented by $\eta $

_{A }and $\eta $_{B}, respectively, then what is the value of $\frac{{\eta}_{B}}{{\eta}_{A}}?$$1.\frac{7}{12}\phantom{\rule{0ex}{0ex}}2.\frac{12}{5}\phantom{\rule{0ex}{0ex}}3.\frac{12}{7}\phantom{\rule{0ex}{0ex}}4.\frac{5}{12}$

Ques.A solenoid of inductance 2H carries a current of 1 A. What is the magnetic energy stored in a solenoid ?(1) 2 J (2) 1 J

(3) 4 J (4) 5

Illustration 5.Five point charges, each of value +q are placed of five vertices of a regular hexagon of side L. What is the magnitude of the force on a point charge of value-q placed at the centre of the hexagon ?(a) frequency and velocity

(b) frequency and wavelength

(c) wavelength and velocity

(d) frequency, wavelength and velocity

42. A fork gives 5 beats with a 40 cm length of sonometre wire. If the length ofthe wire is shortened by 1 cm, the number of beats is still the same. The frequency of the fork is

(a) 385 Hz

(b) 600 Hz

(c) 395 Hz

(d) 400 Hz

Q38. The heart beat of a person is 90 per minute. The frequency is

(a) 90 Hz (b) 60 Hz

(c) 1.33 Hz (d) 1.5 Hz