A radioactive nucleus is being produced at a constant rate per second. Its decay constant is λ. If N0 are the number of nuclei at time t = 0, then the maximum number of nuclei possible are
N0 +
N0
+ N0
In a concave mirror, an object is placed at a distance d1 from the focus and the image is formed at a distance d2 from the focus. Then the focal length of the mirror is
d1 d2
(d1 + d2 )/ 2
A short linear object, of length l, lies along the axis of a concave mirror, of focal length f, at a distance d from the pole of the mirror. The size of the image is then (nearly)
Assertion: A total reflecting prism is used to erect the inverted image without deviation.
Reason: Rays of light incident parallel to base of prism emerge out as parallel rays.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false.
Assertion: The edges of the images of white object formed by a concave mirror on the screen appear white.
Reason: Concave mirror does not suffer chromatic aberration.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false
Assertion: A photon has no rest mass, yet it carries definite momentum.
Reason: Momemtum of photon is due to its energy and hence its equivalent mass.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false
Assertion: A photocell is called an electric eye.
Reason: When light is incident on some semiconductor its electrical resistance is reduced.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false
Assertion: Nuclei having mass number about 60 are most stable.
Reason: When two or more light nuclei are combined into a heavier nucleus, then the binding energy per nucleon will increase.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false
Assertion: In a common-emitter amplfier, the load resistance of the output circuit is 1000 times the load resistance of the input circuit. If = 0.98, then voltage gain is 49 x 103.
Reason: ( symbols have their usual meaning ).
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false
C.
If assertion is true but reason is false
(alpha) of a transistor is the factor or value that an emitter current is multiplied by to give the value of the collector current.
We know that
Also we know about
β = 49
∴ Voltage gain
β =
= 49 × 1000
β = 49 × 103
Assertion: Most amplifiers use common emitter circuit configuration.
Reason: Its input resistance is comparatively higher.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false