CBSE 11TH PHYSICS - Online Test

Answer : Option B
Explaination / Solution:

In isothermal process

W=nRTloge(VfVi)

W=1×8.31×273×2.303log10103=2.7×103J

Answer : Option D
Explaination / Solution:

When the lift moves upward with acceleration = 5 ms-2 the net force acting upward

R−mg=maR=mg+maR=m(g+a)R=70(10+5)R=1050N

R = 1050 N

(We experience weight due to reaction)

therefore Apparent weight = =1050g=105010=105 kg

Answer : Option C
Explaination / Solution:

Work done by force applied against gravity for one lift will be

W=Fs=mgh=10×9.8×0.5=49J

So work done for 1000 lifts = 49 x 1000 = 49000 J

efficiency = Work done / energy from fat

energy from fat used =Work done / efficiency

E=Wη=490000.2=245000J

Energy from per kilogram fat =  3.8 ×$\times$ 107 J

Fat used =2450003.8×107=64473×10−7=6.45×10−3Kg

Answer : Option A
Explaination / Solution:

If an invention that only cause harm to the society, it should be in safe hands only and the safe hands are only who discovered it. So it's better to keep the information upto you and your colleagues, so that all of them can work on it to make it useful for society.

Answer : Option D
Explaination / Solution:

As angular momentum  is L⃗ =p⃗ ×r⃗ =mvrsinθ , Now rsinθ=perpendicular distance from x axis which is constant,  so angular momentum is  remains constant.

Answer : Option A
Explaination / Solution:
No Explaination.

Answer : Option D
Explaination / Solution:

PV=NkTN=PVkT=1.01×105×(43×3.14×(0.15)3)1.38×10−23×293=3.53×1023

Answer : Option A
Explaination / Solution:

Change in diameter

Δl=αlΔT=1.70×10−5×4.24×200=1.44×10−2cm

Answer : Option C
Explaination / Solution:

There are three rules on determining how many significant figures are in a number:

• Non-zero digits are always significant.
• Any zeros between two significant digits are significant.
• A final zero or trailing zeros in the decimal portion ONLY are significant.

So keeping these rules in mind, there are 4 significant digit.

Answer : Option B
Explaination / Solution:
No Explaination.