Tags Physics

Physics

Get insights from 5.6k questions on Physics, answered by students, alumni, and experts. You may also ask and answer any question you like about Physics

Follow Ask Question

5.6k

Questions

Discussions

Active Users

Followers

New answer posted

4 months ago

Physics Atoms

If an electron is moving in the nth orbit of the hydrogen atom, then its velocity (v_n) for the nth orbit is given as :

0 Follower 2 Views

Vishal Baghel

Contributor-Level 10

Velocity of an electron in the nth orbit:

v ∝ 1/n

0 0

New answer posted

4 months ago

Physics Class 11th

Two identical metal of thermal conductivities K₁ and K₂ respectively are connected in series. The effective thermal conductivity of the combination is:

0 Follower 9 Views

Vishal Baghel

Contributor-Level 10

R_eq = R? + R?

L_total / (K_eq * A) = L? / (K? A) + L? / (K? A)
Assuming L? = L? = l, L_total = 2l

2l / (K_eq * A) = l/ (K? A) + l/ (K? A)

2/K_eq = 1/K? + 1/K? = (K? + K? )/ (K? )

K_eq = 2K? K? / (K? + K? )

0 0

New answer posted

4 months ago

Physics Thermodynamics

Two ideal polyatomic gases at temperatures T₁ and T₂ are mixed so that there is no loss of energy. If F₁ and F₂, m₁ and m₂, n₁ and n₂ be the degrees of freedom, masses, number of molecules of the first and second gas respectively, the temperature of mixture of these two gases is:

0 Follower 3 Views

Vishal Baghel

Contributor-Level 10

U = U? + U? = (n? /N_A) (F? R/2)T? + (n? /N_A) (F? R/2)T?

For the mixture: U = (n? +n? )/N_A * (FR/2)T

F = (n? F? + n? F? ) / (n? + n? )

Equating the expressions for U and solving for T gives:
T = (n? F? T? + n? F? T? ) / (n? F? + n? F? )

0 0

New answer posted

4 months ago

Physics Class 12th

An AC current is given by I = I₁sinωt + I₂cosωt. A hot wire ammeter will give a reading:

0 Follower 13 Views

Vishal Baghel

Contributor-Level 10

I = I? sin (ωt) + I? cos (ωt)

This can be written as I = I? sin (ωt + φ), where I? = √ (I? ² + I? ²)

A hot wire ammeter reads the rms value of the current.

I_rms = I? /√2 = √ (I? ² + I? ²)/√2

0 0

New answer posted

4 months ago

Physics Oscillations

For what value of displacement the kinetic energy and potential energy of a simple harmonic oscillation become equal?

0 Follower 2 Views

Vishal Baghel

Contributor-Level 10

K = U

½ mω² (A² - x²) = ½ mω²x²

A² - x² = x²

A² = 2x²

x = ± A/√2

0 0

New answer posted

4 months ago

Physics Class 11th

When two soap bubbles of radii a and b (b > a) coalesce, the radius of curvature of common surface is:

0 Follower 9 Views

Vishal Baghel

Contributor-Level 10

P? - P? = 4T/a

P? - P? = 4T/b

P? - P? = 4T (1/a - 1/b)

Also, P? - P? = 4T/r

4T/r = 4T (1/a - 1/b)

1/r = (b-a)/ab

r = ab / (b-a)

0 0

New answer posted

4 months ago

Physics Thermodynamics

A Carnot's engine working between 400 K and 800 K has a work output of 1200J per cycle. The amount of heat energy supplied to the engine from the source in each cycle is:

0 Follower 2 Views

Vishal Baghel

Contributor-Level 10

η = 1 - T_C / T_H

η = 1 - 400/800 = 1 - ½ = ½

η = W/Q_H ⇒ ½ = W/Q_H ⇒ Q_H = 2W = 2 * 1200 = 2400 J

0 0

New answer posted

4 months ago

Physics Physics Moving Charges and Magnetism

A solenoid of 1000 turns per meter has a core with relative permeability 500. Insulated windings of the solenoid carry an electric current of 5 A. The magnetic flux density produced by the solenoid is: (permeability of free space = 4π*10^-7H/m)

0 Follower 2 Views