Light wave enters from medium 1 to medium 2. Its velocity in 2nd medium is double from 1st. For total internal reflection the angle of incidence must be greater than
|
(a) 30o |
(b) 60 o |
(c) 45 o |
(d) 90 o |
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AB and CD are long straight conductor, distance d apart, carrying a current I. The magnetic field at the midpoint of BC is
|
(a) |
(b) |
(c) |
(d) |
A current of 10 ampere is flowing in a wire of length 1.5 m. A force of 15 N acts on it when it is placed in a uniform magnetic field of 2 tesla. The angle between the magnetic field and the direction of the current is
|
(a) 30 ° |
(b) 45 ° |
(c) 60 ° |
(d) 90 ° |
A battery is charged at a potential of 15 V for 8 hours when the current flowing is 10 A. The battery on discharge supplies a current of 5 A for 15 hours. The mean terminal voltage during discharge is 14 V. The "Watt-hour" efficiency of the battery is
|
(a) 82.5% |
(b) 80 % |
(c) 90% |
(d) 87.5% |
Immiscible transparent liquids A, B, C, D and E are placed in a rectangular container of glass with the liquids making layers according to their densities. The refractive index of the liquids are shown in the adjoining diagram. The container is illuminated from the side and a small piece of glass having refractive index 1.61 is gently dropped into the liquid layer. The glass piece as it descends downwards will not be visible in
|
(a) Liquid A and B only |
(b) Liquid C only |
|
(c) Liquid D and E only |
(d) Liquid A, B, D and E |
An electron enters between two horizontal plates separated by 2mm and having a potential difference of 1000V. The force on electron is
|
(a) 8 |
(b) 8 |
(c) 8 |
(d) 8 |
The drift velocity does not depend upon
|
(a) Cross-section of the wire |
(b) Length of the wire |
|
(c) Number of free electrons |
(d) Magnitude of the current |
The variation of magnetic susceptibility (x) with magnetising field for a paramagnetic substance is
|
(a)
|
(b)
|
(c)
|
(d)
|
Seven resistances are connected as shown in the figure. The equivalent resistance between A and B is
|
(a) 3 W |
(b) 4 W |
(c) 4.5 W |
(d) 5 W |
Continuous spectrum is not due to
|
(a) Hydrogen flame |
(b) Electric bulb |
|
(c) Kerosene oil lamp flame |
(d) Candle flame |
