Enable contrast version

# Tutor profile: Ravi S.

Inactive
Ravi S.
Tutor of physics from 9 years
Tutor Satisfaction Guarantee

## Questions

### Subject:Physics (Newtonian Mechanics)

TutorMe
Question:

An automobile of mass m accelerate starting from rest with supply of constant power P. Find it’s instantaneous velocity as a function of time.

Inactive
Ravi S.

Fv = P m.dv/dt = P Integration (Pdt/m) = integration (vdv) By integrating V^2 /2 = Pt/m + C Using initial conditions At t= 0 , v=0 so C=0 Solving v = (2Pt/m)^(1/2)

### Subject:Physics (Electricity and Magnetism)

TutorMe
Question:

A heater operate with power of 1200 W in 100 V line.It is connected in combination with a resistance of 10 ohm and a resistance r, to a 100 V mains as shown in figure. What will be the value of r so heater operates with power 62.5W.

Inactive
Ravi S.

P=V^2/R Resistance of heater R = 100^2/1200 R = 8.33ohm For second case P =62.5 W I=(62.5/8.333) i= 2.73A Main current in circuit I = 100/(10+(10r/10+r)) This current will distribute at parallel combination i = I(r/10+r) Solving r = 6 ohm

### Subject:Physics

TutorMe
Question:

A flat disc of radius r has surface charge density s. The disc rotated about an axis perpendicular to its plane and passing through its centre with angular speed w.find the torque on the disc if it is placed in a uniform magnetic field B directed parallel to plane of disc.

Inactive
Ravi S.

We consider a ring of radius x and very small width Dixon the disc. Charge on the ring dq = s.2 pi x dx Current due to this charge I = dq . Frequency I = s 2 pi x dx . w /2.pi I = swxdx Magnetic moment of ring M = I.A M = swxdx . Pi . X^2 Torque on ring dT = MB sin theta Theta = 90 degrees dT = swpiBx^3 dx Torque T = integration(dT) from 0 to r T = (swpiB r^4)/4

## Contact tutor

Send a message explaining your
needs and Ravi will reply soon.
Contact Ravi