In double slits experiment, for light of which colour the fringe width will be minimum
|
(a) Violet |
(b) Red |
(c) Green |
(d) Yellow |
In double slits experiment, for light of which colour the fringe width will be minimum
|
(a) Violet |
(b) Red |
(c) Green |
(d) Yellow |
(a) Violet
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An object is placed at a distance u from a simple microscope of focal length f. The angular magnification obtained depends:
The decay constant of a radioactive element is 1.5
per second. Its mean life in seconds will be
|
(a) 1.5 |
(b) 4.62 |
(c) 6.67 |
(d) 10.35 |
Two slits, 4 mm apart, are illuminated by light of wavelength 6000 Å. What will be the fringe width on a screen placed 2m from the slits
|
(a) 0.12 mm |
(b) 0.3 mm |
(c) 3.0 mm |
(d) 4.0 mm |
The plate current in a triode is given by where Ip, Vp and Vg are the values of plate current, plate voltage and grid voltage, respectively. What are the triode parameters m, rp and gm for the operating point at
and
?
|
(a) 10, 16.7 kW, 0.6 m mho |
(b) 15, 16.7 kW, 0.06 m mho |
|
(c) 20, 6 kW, 16.7 m mho |
(d) None of these |
If the momentum of a photon is p, then its frequency is (Where m is the rest mass of the photon)
|
(a) |
(b) |
(c) |
(d) |
The angle between the earth's magnetic and the earth's geographical axes is
| (a) Zero | (b) 17° | (c) 23° | (d) None of these |
A conducting wire frame is placed in a magnetic field which is directed into the paper. The magnetic field is increasing at a constant rate. The directions of induced current in wires AB and CD are

|
(a) B to A and D to C |
(b) A to B and C to D |
|
(c) A to B and D to C |
(d) B to A and C to D |
Ge and Si diodes conduct at 0.3 V and 0.7 V respectively. In the following figure if Ge diode connection are reversed, the valve of V0 changes by
|
(a) 0.2 V |
(b) 0.4 V |
(c) 0.6 V |
(d) 0.8 V |
In the circuit shown here, E1 = E2 = E3 = 2 V and R1 = R2 = 4 ohms. The current flowing between points A and B through battery E2 is
|
(a) Zero |
(b) 2 amp from A to B |
|
(c) 2 amp from B to A |
(d) None of the above |