CBSE 11TH PHYSICS - Online Test

Answer : Option C
Explaination / Solution:

Initial velocity u = 2 m/s

final velocity = v m/s

Time duration = final time - initial time = 2-0 = 2 s

acceleration a = 2 m/s​​​​​​2

We know,

v = u + at

=> v = 2+2×2

=> v = 6 m/s

Answer : Option B
Explaination / Solution:
No Explaination.

Answer : Option C
Explaination / Solution:

The car is in uniform circular motion because it’s moving at a constant speed along a curve that is a segment of a circle. Hence we know 

R=v2arad= (40)29.4=170 m 

This is the minimum turning radius because arad is the maximum centripetal acceleration.

Answer : Option B
Explaination / Solution:
No Explaination.

Answer : Option C
Explaination / Solution:

in isobaric process

W=nR(Tf−Ti)

W=0.2×8.31(300−20)=466J

Answer : Option C
Explaination / Solution:

Let, T= tension on the string

a = acceleration, m1 = mass of light body= 10 kg and m2= mass of heavy body = 20 kg

a=Fm1+m2=60030=20ms−2

Now the tension in the string will be,

T=m2a=20×20=400N

Answer : Option A
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

Time taken by the boy to run t = 10/4 = 2.5 sec

Distance moved by the trolley = v,t=10.36×2.5=25.9m

Answer : Option D
Explaination / Solution:

Moment of inetia of axis passing through its center and perpendicular to its plane:

 I = ½ MR2

Using perpendicular axis theorem   Ix +Iy = Iz  ,so  2Id = ½ MR2

Moment of inetia of  along its diameter  Id = ¼MR2

And the radius of gyration    MK2  = ¼MR2   

R2

 

Answer : Option C
Explaination / Solution:
No Explaination.

Answer : Option A
Explaination / Solution:

In nuclear physics, beta decay (β-decay) is a type of radioactive decay in which a beta ray (fast energetic electron or positron), and a neutrino are emitted from an atomic nucleus. For example, beta decay of a neutron transforms it into a proton by the emission of an electron, or conversely a proton is converted into a neutron by the emission of a positron (positron emission), thus changing the nuclide type.