The potential difference in open circuit for a cell is 2.2 volts. When a 4 ohm resistor is connected between its two electrodes the potential difference becomes 2 volts. The internal resistance of the cell will be
|
(a) 1 ohm |
(b) 0.2 ohm |
(c) 2.5 ohm |
(d) 0.4 ohm |
(d) 0.4 ohm
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A wire of length 5 m and radius 1 mm has a resistance of 1 ohm. What length of the wire of the same material at the same temperature and of radius 2 mm will also have a resistance of 1 ohm
|
(a) 1.25 m |
(b) 2.5 m |
(c) 10 m |
(d) 20 m |
Figure here shows P and Q as two equally intense coherent sources emitting radiations of wavelength 20 m. The separation PQ is 5.0 m and phase of P is ahead of the phase of Q by 90o. A, B and C are three distant points of observation equidistant from the mid-point of PQ. The intensity of radiations at A, B, C will bear the ratio
|
(a) 0 : 1 : 4 |
(b) 4 : 1 : 0 |
(c) 0 : 1 : 2 |
(d) 2 : 1 : 0 |
An inductance L and a resistance R are first connected to a battery. After some time the battery is disconnected but L and R remain connected in a closed circuit. Then the current reduces to 37% of its initial value in
|
(a) RL sec |
(b) |
(c) |
(d) |
The bluish colour of water in deep sea is due to:
A circular disc is placed in front of a narrow source. When the point of observation is at a distance of 1 meter from the disc, then the disc covers first HPZ. The intensity at this point is I0. The intensity at a point distance 25 cm from the disc will be
|
(a) |
(b) |
(c) 
|
(d) 
|
The network shown in the figure is a part of a complete circuit. If at a certain instant the current i is 5 A and is decreasing at the rate of 
then 
is
|
(a) 5 V |
(b) 10 V |
(c) 15 V |
(d) 20 V |
