575 - Physics Questions Answers
Q E=ELECTROMAG F, G=GRAVT.F, N = NUCLEAR F B/W 2 e- AT A GIVEN PTN. THEN E>G>N HOW=? BECAUSE G< THEN OTHER FORCES.
for the distance upto fermi level order will be N>E>G
but the distance between electrons is greater than fermi level so the given order is justified because now nuclear forces will be very weak.
Q A PARTICLE START MOVING FROM REST STATEVALONG A STRAIGHT LINE UNDER ACTION OF A CONST. F & TRAVEL DIST. X IN FIRST 5 sec THE DIST. TRAVELLED IN NEXT 5 sec WILL BE=?
QA CUBE OF A SIDE a IS HEATED TO RAISE ITS TEMP. BY 3*C IF Y IS COEFF. OF VOL. EXPANSION THEN TOTAL INCREASE IN AREA=? (ANS 12Yasqure. )
WAVES & OCILL. Q OBSV. IS MOVING TOWARDS A SOURCE AT REST WITH 30m/s if sound is sounding a sound of freq 500Hz & speed of sound is 300m/s then wavelenth by obsv. =?
Q TEMP. OF GAS INCREASED BY 2K KEEPING PRESS. CONST. SPEED OF SOUND IN GAS=? ans=1.22m/s
Q THE MASS OF ELEVATOR = 4000kg .STARTING FROM REST HOW MUCH DIST. WILL IT RISE IN 2s IF TENSION =56 kN . I want to know why we use ,' a ' for cal. dist. why 'a+g' is NOT use.
by formula s = ut + 1/2 a t2
u = 0 [given]
so s = 1/2 a (5)2= 25a/2 for first 5 sec.
and s = 1/2 a (10)2 = 50a for total 10 sec. from start
so for next 5 sec. distance = 50a - 25a/2 = 75a/2
answer : a'3 = a3 (1+ γ3) here a' is the side of the cube after heating it
so a' = a (1+3γ)1/3
so area increment = 6a'2 - 6a2 = 6a2 [(1+3γ)2/3 - 1] = 6a2 [ 2γ] = 12γa2
Please submit all the questions seperately.
λ = v/n = 300/500
i think you are asking about increment in speed
so according to formula v'/v = [(T+2)/T]1/2
or v'/v = 1 + (1/T)
so v' - v = v(1/T) = 332*1/273 = 1.22 here 332 is the speed of sound at 273K
when a machine works , you should not count gravity, for example if we raise our hand upword with uniform velocity then gravity makes no problem in it because our hand is working by our internal capabilitites
Q A PARTICLE STARTS MOVING WITH ACC.=2m/s 2 DISTANCE TRAVELLED BY IT IN 5th HALF SECOND IS=?
Q A PARTICLE MOVES IN A STRAIGHT LINE & ITS POSITION X AT TIME t IS GIVEN BY X RAISED TO P. 2=2+t . ACC. IS GIVEN BY=? (ans . -2/4t cube)
first calculate distance of 4 seconds by using s = ut + 1/2 a t2
then distance of 4.5 sec. by same formula
difference of these 2 is the distance of 5th half sec.
but some writter consider 5th half as 1/2 +1/2+1/2+1/2+1/2 means 2.5
so they use the same formula first for 2 sec then for 2.5 sec, then their difference.
according to my opinion first is more true way to solve.
Dear Sarika please submit only one question in a box, for a new question use another box so that i could give answers more quickly.
According to the given condition
x2 = 2+t
on differentiaing we get 2x dx/dt = 1
or v = 1/2x
now differentiate it again we get dv/dt = -(1/2x2 )(dx/dt) = -(1/2x2 )(-1/2x) = 1/4x3
Q HEAT & WORK ARE EQUIVALENT. THIS MEANS
TEMP OF BODY CAN BE INCREASED BY DOING WORK ON IT. PLS TELL HOW THIS STAT. IS CORRECT.Q
Q IF H IS SUPPLIED TO IDEAL GAS IN ISO PROCESS. THEN W= +ve HOW? BECAUSE IF ISO THEN U= 0 & EQN IS Q=W+0 & H IS SUPPLIED SO Q=-veSO W =-ve.so ans shd be -veBUT ANS GIVEN IS +ve PLS TELL ANS WITH EXPL. THANKS FOR PRE SOLUTIONS .
This means heat can be used to make work and work done produces heat
By doing 4.2 joule work 1 cal. heat will be produced in a body so due to this 1 cal, temp. will increase
In physics heat is supplied means Q will be +ve so W will also be positive hence is correct. A system is placed in refrigrator for absorbing heat from the body, this process will have Q -ve.
Q IF Al DIPPED IN H2O AT 10*C THEN FORCE OF BUOYANCY WILL INCREASE OR DECREASE?
Q TEMP. OF A SOLID OBJECT IS OBSV. CONST .DURING A PERIOD . IN THIS PERIOD
a)HEAT MAY HAVE BEEN SUPPLIED TO IT
b) H MAY HAVE BEEN EXTRACTED FROM IT
c) no H SUPPLIED TO IT
d)NO H EXTRACTED FROM IT
more than one opt is correct . pls explain your each opt with expln.
It depends that either Al or water will change its density more rapidly, because Bouyancy is based on densities of solid and liquid
Answer : a, because it may be an isothermal process
b, because in isothermal process, surrounding can also give heat to the system.
c, may be the process is adiabatic
d, may be adiabatic.
Q gas of certain mass at 273K is expanded to 81 times its vol. under adia. condition. if gamma = 1.25 for gas then its final temp. = ?
Q for a const. vol. gas thermometer one should fill gas at high temp & low pressure WHY ?
Q iF TEMP of uniform rod is slightly increase by del T its moment of inertia about 90* bisector increase BY = ? (ANS 2alpha I del T ).
Q Al sphere is dipped into H2O at 100*C if temp is increased forse of buoyancy will inc. OR decreased WHY =?
DENSITY OF A SUB. IS 10g/cc at 0*C &at 100*C d= 9.7 g/cc . coeff. of linear expantion is =?
Answer : For adiabatic process TVγ-1 = K
so 273*V0.25 = T*(81V)0.25
so 273/3 = T
Answer : Because real gases perform ideal behaviour in this range.
Answer : Inertia about perpendicular bisector = 1/12 ML2
on increasing temperature by dT new inertia = 1/12 M[L(1+αdT)]2
so increment in inertia = 1/12 ML2 [(1+αdT)2-1-] = 1/12 ML2 [ (αdT)2 + 2αdT ] now neglect (αdT)2 because it is small term
Answer : Since temperature is already 100 degree centigrade so on increasing it further density of Al will increase rapidly in comparision to density of water so Buoyancy force will be increased.
Answer : use the formula d100 = d0 / (1+γ100) here γ=3α calculate α
Q Agraph having temp *C along xaxis& *F along y axis. if graph is straight then it intercept +ve y axis. WHY ?
(F-32)/9 = t/5
so F = 9t/5 + 32
on taking t = 0 we will get F = 32
thats why it makes an intercept of 32 in y axis
sir, can u please post a topic on rigid body rotation ? mainly heip to solve question please. with some examples.
Yes, I will do very soon.
Q 1-when current passes through a solenoid .then what happens to the length of solenoid?
Q2-a current carrying wire carrying current i normally into the paper at the centreof current carring circular ring.the magnetic force acting on the circular ring is ?
Q3- To increase the current through the solenoid from 1A TO 2A ,30J work is done by thr battery.work done by the same battery in increasing the current from 3A TO 4A IS?
Q4- When a closed looop is held stationary in magnetic field b/w north & south pole of 2 permanent magnets of different dipole moments , then current will be induced in the loop or not?
1. the length will decrease as the current in the two consecutive turns of the solenoid are in same direction. which will create an atrraction.
2. since B produced by the wire is parllel to the direction of dl so net force will be 0
3.dw = Lidi first take limit 1 to2 and w=30 to find the L (INTEGERATE)
After than again use the above formula taking limit 3 to 4 .put L here ,L= 20
the answer is 70J.
4. I think no emf will be induced as the flux is not changing.
These answers by NIKHIL VARSHNEY are correct
a uniformrope of lenth 10 m and mass 12 kg hangs verticaly from a rigid support . a block of mass 4 kg is attached to the free end of the rope . atrans verse wave of wavelenth 00.03 m is prodused at the lower end . wavelenth of pulse when it reaches upper end will be?
at top point tension in the string = 16g
and at bottom point T = 4g
and v = √(T/m) here m is mass per unit length which is same throughout the rope.
first calculate v at both the points
frequency will be same throughout
so use the formula v = nλ twice
once at bottom and once at top point
then by diving these 2 formulae we will get the result
try it.