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 X-axis 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 X-axis, 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?
A 2 kg mass is rotating on a circular path of radius 0.8 m with angular velocity of 44 rad-s-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 µ2 = 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 µ1 = 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)cosω0t,
where a is a constant, ω = 12 × 1014 rads–1 and ω0 = 3.6 × 1015 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 (λmax) 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 ES = 10 V and r = 1Ω in 1st reading and ES = 5V and r = 2Ω in 2nd 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 1m2, 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.