X-rays which can penetrate through longer distances in substance are called
|
(a) Soft X-rays |
(b) Continuous X-rays |
(c) Hard X-rays |
(d) None of the above |
(c) Hard X-rays
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
AB is a wire of uniform resistance. The galvanometer G shows no current when the length AC = 20cm and CB = 80 cm. The resistance R is equal to
|
(a) 2 Ω |
(b) 8 Ω |
(c) 20 Ω |
(d) 40 Ω |
The half-life period of radium is 1600 years. Its average life time will be
|
(a) 3200 years |
(b) 4800 years |
(c) 2319 years |
(d) 4217 years |
and 
are the focal lengths of a convex lens for violet and red light respectively and 
and 
are the focal lengths of a concave lens for violet and red light respectively, then
|
(a) |
(b) |
|
(c) |
(d) |
In the spectrum of light of a luminous heavenly body the wavelength of a spectral line is measured to be 4747 Å while actual wavelength of the line is 4700 Å. The relative velocity of the heavenly body with respect to earth will be (velocity of light is 3
)
|
(a) 3 |
|
(b) 3 |
|
(c) 3 |
|
(d) 3 |
A two metre wire is moving with a velocity of 1 m/sec perpendicular to a magnetic field of 0.5 weber/m2. The e.m.f. induced in it will be
|
(a) 0.5 volt |
(b) 0.1 volt |
(c) 1 volt |
(d) 2 volt |
The capacitor of capacitance 4 μF and 6 μF are connected in series. A potential difference of 500 volts is applied to the outer plates of the two capacitor system. The potential difference across the plates of capacitor of 4 μF capacitance is
|
(a) 500 volts |
(b) 300 volts |
(c) 200 volts |
(d) 250 volts |
A small coil C with N = 200 turns is mounted on one end of a balance beam and introduced between the poles of an electromagnet as shown in figure. The cross sectional area of coil is A= 1.0 cm2, length of arm OA of the balance beam is l = 30 cm. When there is no current in the coil the balance is in equilibrium. On passing a current I = 22 mA through the coil the equilibrium is restored by putting the additional counter weight of mass ∆m = 60 mg on the balance pan. Find the magnetic induction at the spot where coil is located.
|
(a) 0.4 T |
(b) 0.3 T |
(c) 0.2 T |
(d) 0.1 T |
The kinetic energy of an electron is 5 eV. Calculate the de-Broglie wavelength associated with it (h = 6.6 × 10–34 Js, me = 9.1 × 10–31 kg)
|
(a) 5.47 Å |
(b) 10.9 Å |
(c) 2.7 Å |
(d) None of these |
