Explanation:
As the uniform sphere is placed on a smooth surface, the sphere only slips.
The acceleration of the centre of the sphere is given by,
$\frac{\text{Applied force}}{\text{Mass of the sphere}},$ which is independent of height h.
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
In hydrogen atom, the electron makes 6.6 
revolutions per second around the nucleus in an orbit of radius 0.5 
. It is equivalent to a current nearly
|
(a) 1 A |
(b) 1 mA |
(c) 1 μA |
(d) 1.6 |
The direction of ray of light incident on a concave mirror is shown by PQ while directions in which the ray would travel after reflection is shown by four rays marked 1, 2, 3 and 4 (Fig). Which of the four rays correctly shows the direction of reflected ray?
The rate of disintegration was observed to be 
disintegrations per sec when its half life period is 1445 years. The original number of particles are
(a) 8.9 
|
(b) 6.6
|
(c) 1.4 
|
(d) 1.2 
|
In determining the temperature of a distant star, one makes use of
|
(a) Kirchhoff's law |
(b) Stefan's law |
|
(c) Wien's displacement law |
(d) None of these |
An electron moving in a circular orbit of radius r makes n rotation per second. The magnetic field produced at the centre has a magnitude of
|
(a) |
(b) |
(c) |
(d) Zero |
Assertion : Electric conduction in gases is possible at normal pressure.
Reason : The electric conduction in gases depends only upon the potential difference between the electrodes.
|
(a) If both assertion and reason are true and the reason is the correct explanation of the assertion. |
|
(b) If both assertion and reason are true but reason is not the correct explanation of the assertion. |
|
(c) If assertion is true but reason is false. |
|
(d) If the assertion and reason both are false. |
Assertion : The induced e.m.f. and current will be same in two identical loops of copper and aluminium, when rotated with same speed in the same magnetic field.
Reason : Induced e.m.f. is proportional to rate of change of magnetic field while induced current depends on resistance of wire.
|
(a) If both assertion and reason are true and the reason is the correct explanation of the assertion. |
|
(b) If both assertion and reason are true but reason is not the correct explanation of the assertion. |
|
(c) If assertion is true but reason is false. |
|
(d) If assertion is false but reason is true. |
