Quantity that remains unchanged in a transformer is
Two bodies of mass 10 kg and 5 kg moving in concentric orbits of radii R and r such that their periods are the same. Then the ratio between their centripetal acceleration is
An electric dipole is placed along the Xaxis at the origin O. A point P is at a distance of 20 cm from this origin such that OP makes an angle π/3 with the X axis. If electric field at P makes an angle θ with Xaxis, the value of θ is
A semi circle arc of radius 'a' is charged uniformly and the charge per unit length is λ. The electric field at its centre is
The figure shows the symbol of a
Which of the following equations is definitely wrong?
For a gas, if the ratio of specific heats at constant pressure and volume is γ, then the value of degree of freedom is
Cp=(f/2+1)RT
Cv= (f/2)RT
Taking ratio we get
Cp/Cv = y = (f/2 + 1)/(f/2)
y=(f + 2)/f
y=1 + 2/f
y 1=2/f
f = 2/(y1)
Hope it helps
A 2 kg mass is rotating on a circular path of radius 0.8 m with angular velocity of 44 rads^{1}. If radius of the path becomes 1 m, then value of angular velocity will be
Which is not a unit of electric field
In a mixture of H−He^{+} gas (He^{+} is singly ionized He atom) , H atoms and He^{+} ions are excited to their respective first excited states. Subesquently, H atoms transfer their total excitation energy to He^{+} ions (by collisions). Assume that the Bohr model of atom is exactly vaild.
Q. The quantum number n of the state finally populated in He^{+} ions is
A biconvex thin lens is prepared from glass of refractive index µ_{2} = 3/2. The two converging surface have equal radii of 20cm each. One of the surface is silvered from outside to make it reflecting. It is placed in a medium of refractive index µ_{1} = 5/3. This system will behave as concave mirror of focal length f, find value of f in cm.
Find the maximum kinetic energy (in eV) of the photoelectron liberated from the surface of lithium (work function φ = 2.15eV) by electromagnetic radiation whose electric component varies with time as E = a (1 + cos ωt)cosω_{0}t,
where a is a constant, ω = 12 × 10^{14} rads^{–1} and ω_{0} = 3.6 × 10^{15} rads^{–1} (h = 6.6 × 10^{–34} in SI units)
A photosensitive surface is irradiated with light of wavelength λ, the stopping potential is V. When the same surface is irradiated with the light of wavelength 2λ, stopping potential is V/3. Then the ratio of threshold wavelength (λ_{max}) and the λ is
One of the circuits for the measurement of resistance by potentiometer is shown. The galvanometer is connected at point A and zero deflection is observed at length PJ = 30 cm. In second case the secondary cell is changed. Take E_{S} = 10 V and r = 1Ω in 1^{st} reading and E_{S} = 5V and r = 2Ω in 2^{nd} reading. In second case, the zero deflection is observed at length PJ = 10 cm. What is the resistance R (in ohm)?
A uniform triangular plate of triangular area 1m^{2}, base length 60 cm and thickness 10 mm (prism like shape) is lying vertically on a smooth ground as shown in figure. Find maximum value of cotθ for which it does not topple.







