KVPY Stream SB-SX (Class 12 & 1st Year BSC) Physics: Questions 221 - 223 of 250

Get 1 year subscription: Access detailed explanations (illustrated with images and videos) to 250 questions. Access all new questions we will add tracking exam-pattern and syllabus changes. View Sample Explanation or View Features.

Rs. 200.00 or

Question number: 221

» Gravitation » Gravitational Potential

MCQ▾

Question

Two masses m1 = 10 kg and m2 = 810 kg are held 2 m apart. At a point P on the line joining them is the gravitational field equal to zero. The gravitational potential at that point is –

Choices

Choice (4) Response

a.

3.33×108Jkg1

b.

3.33×1011Jkg1

c.

6.67×108Jkg1

d.

6.67×1011Jkg1

Question number: 222

» Atoms and Nuclei » Bohr Model

Appeared in Year: 2015

MCQ▾

Question

A donor atom in a semiconductor has a loosely bound electron. The orbit of this electron is considerably affected by the semiconductor material but behaves in many ways like an electron orbiting a hydrogen nucleus. Given that the electron has an effective mass of 0.07me, (where me is mass of the electron) and the space in which it moves has a permittivity 13ε0 , then the radius of the electron’s lowermost energy orbit will be close to (The Bohr radius of the hydrogen atom is 0.53 Å)

Choices

Choice (4) Response

a.

10 Å

b.

100 Å

c.

243 Å

d.

0.53 Å

Question number: 223

» Properties of Solids & Liquids » Application of Surface Tension

MCQ▾

Question

A air bubble is formed at the bottom of a lake. When the bubble rises to the surface, its radius increases 4 times. The depth of the lake at that spot is –

Choices

Choice (4) Response

a.

h=16dg(P0+T2r)

b.

h=15dg(P0+T2r)

c.

h=(64dgP0+15Tr)

d.

h=3dg[21P0+10Tr]

Sign In