The mutual inductance between two coils is 1.25 henry. If the current in the primary changes at the rate of 80 ampere/second, then the induced e.m.f. in the secondary is
|
(a) 12.5 V |
(b) 64.0 V |
(c) 0.016 V |
(d) 100.0 V |
(d) 100.0 V
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
At sun rise or sunset, the sun looks more red than at mid-day because
|
(a) The sun is hottest at these times |
(b) Of the scattering of light |
|
(c) Of the effects of refraction |
(d) Of the effects of diffraction |
The current in the adjoining circuit will be
|
(a) |
(b) |
(c) |
(d) |
In P-type semiconductor, there is
|
(a) An excess of one electron |
(b) Absence of one electron |
|
(c) A missing atom |
(d) A donar level |
A galvanometer has a resistance of 25 ohm and a maximum of 0.01 A current can be passed through it. In order to change it into an ammeter of range 10 A, the shunt resistance required is
|
(a) 5/999 ohm |
(b) 10/999 ohm |
(c) 20/999 ohm |
(d) 25/999 ohm |
If two lenses of +5 diopters are mounted at some distance apart, the equivalent power will always be negative if the distance is
|
(a) Greater than 40 cm |
(b) Equal to 40 cm |
|
(c) Equal to 10 cm |
(d) Less than 10 cm |
$\text{zero}$
$\frac{1}{8}\omega\text{Bl}^2$
$\frac{1}{2}\omega\text{Bl}^2$
$\text{B}\omega\text{l}^2$
The magnetic induction at the centre O in the figure shown is
|
(a) |
(b) |
(c) |
(d) |
