CBSE 11TH PHYSICS - Online Test

Answer : Option B
Explaination / Solution:

Hydrogen is a diatomic gas. (CP = 3.5R)

energy transferred by heat to the gas

Q=nCPΔT=1×3.5×8.31×120=3490J=3.49KJ

Answer : Option C
Explaination / Solution:

Thermal Stress =YαΔθ=20×109×11×10−6×40=8.8×106

Answer : Option A
Explaination / Solution:

Value of P is given as 3.763. By rounding off the given value to the first decimal place, we get P = 3.8.

Answer : Option A
Explaination / Solution:
No Explaination.

Answer : Option B
Explaination / Solution:

Initial velocity u = 3 m/s

Acceleration a = 3 m/s​​​​​​2

Initial time t1=0 s

Final time t2=2 s

Time taken t = 2-0= 2 s 

Final velocity v = ?

We know,

v=u+at

=>v=3+2×3

=>v=3+6=9 m/s2

Answer : Option A
Explaination / Solution:
No Explaination.

Answer : Option B
Explaination / Solution:

The speed is constant, so this is uniform circular motion. We are given the radius R=5.0 m and the period T=4.0 s, so we can  calculate the acceleration directly using equation

arad=4(π)2RT2

=4×22×22×5.07×7×4.0×4.0= 12m/s​​​​​​2

Answer : Option C
Explaination / Solution:
No Explaination.

Answer : Option A
Explaination / Solution:

Work done by gas = area under P-V curve

Answer : Option B
Explaination / Solution:

Let, M = mass of nucleus at rest . m1 and m2 are masses of two smaller nuclei. v1 and v2 are the velocities of respective masses

Now, According to the law of conservation of momentum,

Initial momentum before disintegration = final momentum after disintegration

m1v1+m2v2=0

v2=−m2m1⋅v1

As masses m1$m_1$and m2$m_2$ cannot be negative, v1 and v2 having opposite signs and so the two smaller nuclei move in opposite directions.