CBSE 11TH PHYSICS - Online Test

Answer : Option D
Explaination / Solution:

P=αV2α=5.00×1.01×105Vi=1.00m3Vf=2.00m3W=∫1.002.00P.dV=∫1.002.00αV2.dV=[αV33]2.001.00=1.18MJ

Answer : Option D
Explaination / Solution:

Let,

T =tension in the string,

a= acceleration in the direction of force F. 

m1=10 kg and m2= 20 kg

Therefore,common acceleration a=Fm1+m2=60010+20=20ms−2

Now the tension T in the string is T=m1a=10×20=200N

Answer : Option D
Explaination / Solution:

Mass of troly M = 200Kg

mass of child m = 20Kg

speed of trolley v = 36Km/hr=36 x 5/18 = 10m/s

Let v' be the final velocity of the trolley with respect to the ground.

Final velocity of the boy with respect to the ground = v,−4

from conservation of linear momentum

pi=pf(M+m)v=Mv,+m(v,−4)(200+20)×10=200v,+20(v,−4)2200=220v,−80v,=2280220=10.36m/s

 

Answer : Option A
Explaination / Solution:

The nuclear force does not depend upon the charge of nucleons.Nuclear forces usually depend upon the velocity of the nucleons.

Answer : Option D
Explaination / Solution:

Using theorem of parallel axis, the axis is shifted by L/2 distance from centre of Mass where the Moment of Inertia is ML2/12, thus the moment of inertia of a thin rod about an axis passing through one end and perpendicular to its length is  ML2/12 + ML2/4 =13 ML2

Answer : Option D
Explaination / Solution:
No Explaination.

Answer : Option D
Explaination / Solution:

Helium is a monoatomic gas.(CV = 1.5R)

change in internal  energy 

ΔU=nCVΔT=3×1.5×8.31×2=75J

Answer : Option B
Explaination / Solution:

Δl=αlΔθ=11×10−6×30×40=0.013m

Total length after expansion = 30 + 0.013 = 30.013m

Answer : Option C
Explaination / Solution:

length, l = 4.234 m

breadth,b = 1.005 m

thickness, t = 2.01 cm = 2.01 × 10-2 m

volume = l × b × t

=> V = 4.234 × 1.005 × 0.0201 = 0.0855289 = 0.0855 m​​​​​​3 (Significant Figures = 3)

Answer : Option B
Explaination / Solution:
No Explaination.