
- Aq1 and q2, both are positive.
- Bq1 and q2, both are negative.
- Cq1 is positive and q2 is negative.
- Dq2 is positive and q1 is negative.

Explanation:
The filed of lines is outward from the positive charge and inward to the negative charge.
Here the field of lines is towards the charges q1 and q2. Thus, both charges are negative.
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Assertion : The film which appears bright in reflected system will appear dark in the transmitted light and vice-versa.
Reason : The conditions for film to appear bright or dark in reflected light are just reverse to those in the transmitted light.
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(a) If both assertion and reason are true and the reason is the correct explanation of the assertion. |
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(b) If both assertion and reason are true but reason is not the correct explanation of the assertion. |
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(c) If assertion is true but reason is false. |
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(d) If the assertion and reason both are false. |
For a substance the average life for a-emission is 1620 years and for b emission is 405 years. After how much time the 1/4 of the material remains after a and b emission
|
(a) 1500 years |
(b) 300 years |
(c) 449 years |
(d) 810 years |
Assertion : A pulsor is a source of radio waves which change in terms of intensity at regular interval of time
Reason : A pulsor is a rotating neutron star
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(a) If both assertion and reason are true and the reason is the correct explanation of the assertion. |
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(b) If both assertion and reason are true but reason is not the correct explanation of the assertion. |
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(c) If assertion is true but reason is false. |
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(d) If the assertion and reason both are false. |
The coordination number of Cu is
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(a) 1 |
(b) 6 |
(c) 8 |
(d) 12 |
In Millikan oil drop experiment, a charged drop of mass 1.8
is stationary between its plates. The distance between its plates is 0.90 cm and potential difference is 2.0 kilo volts. The number of electrons on the drop is
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(a) 500 |
(b) 50 |
(c) 5 |
(d) 0 |
Antiparticle of electron is
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(a) |
(b) |
(c) Positron |
(d) Neutrino |
For copper-iron (Cu-Fe) couple, the thermo e.m.f. (temperature of cold junction = 0℃) is given by E = (14θ – 0.02)μV. The neutral temperature will be
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(a) 350 ℃ |
(b) 350 K |
(c) 560℃ |
(d) 560 K |
The kinetic energy of an electron revolving around a nucleus will be
| (a) Four times of P.E. | (b) Double of P.E. | (c) Equal to P.E. | (d) Half of its P.E. |