Cathode rays and canal rays produced in a certain discharge tube are deflected in the same direction if
|
(a) A magnetic field is applied normally |
(b) An electric field is applied normally |
|
(c) An electric field is applied tangentially |
(d) A magnetic field is applied tangentially |
(a) A magnetic field is applied normally
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In a coil of self inductance 0.5 henry, the current varies at a constant rate from zero to 10 amperes in 2 seconds. The e.m.f. generated in the coil is
|
(a) 10 volts |
(b) 5 volts |
(c) 2.5 volts |
(d) 1.25 volts |
A boy stands straight infront of a mirror at a distance of 30 cm away from it. He sees his erect image whose height is 
of his real height. The mirror he is using is
|
(a) Plane mirror |
(b) Convex mirror |
(c) Concave mirror |
(d) Plano-convex mirror |
The ratio of de-Broglie wavelength of a a-particle to that of a proton being subjected to the same magnetic field so that the radii of their path are equal to each other assuming the field induction vector 
is perpendicular to the velocity vectors of the a-particle and the proton is
|
(a) 1 |
(b) |
(c) |
(d) 2 |
We use flint glass prism to disperse polychromatic light because light of different colours
|
(a) Travel with same speed |
|
(b) Travel with same speed but deviate differently due to the shape of the prism |
|
(c) Have different anisotropic properties while travelling through the prism |
|
(d) Travel with different speeds |
After five half lives what will be the fraction of initial substance
|
(a) |
(b) |
(c) |
(d) |
Three capacitors of capacitance 1 mF, 2 mF and 3 mF are connected in series and a potential difference of 11 V is applied across the combination. Then, the potential difference across the plates of 1 mF capacitor is
|
(a) 2 V |
(b) 4 V |
(c) 1 V |
(d) 6 V |
A conducting rod of length l is falling with a velocity v perpendicular to a uniform horizontal magnetic field B. The potential difference between its two ends will be
|
(a) 2Blv |
(b) Blv |
(c) |
(d) |
The emf of a thermocouple, one junction of which is kept at 0℃, is given by 
the Peltier co-efficient will be
|
(a) (t + 273) (a + 2bt) |
(b) (t + 273) (a – 2bt) |
|
(c) (t – 273) (a- 2bt) |
(d) (t – 273) (a – 2bt) |
The line joining the pole and the centre of curvature of a mirror is called the:
