Semiconductor Electronic: Material, Devices And Simple Circuits — Physics STD 12 Science — Question

A vertical straight conductor carries a current vertically upwards. A point P lies to the east of it at a small distance and another point Q lies to the west at the same distance. The magnetic field at P is(a) Greater than at Q(b) Same as at Q(c) Less than at Q(d) Greater or less than at Q depending upon the strength of the current

Identify the type of materials which develop electric currents in them, when an electric field is applied.

A person A can clearly see objects between 25cm and 200cm. Which of the following may represent the range of clear vision for a person B having muscles stronger than A, but all other parameters of eye identical to that of A?

1. 25cm to 200cm.
2. 18cm to 200cm.
3. 25cm to 300cm.
4. 18cm to 300cm.

Two lithium nuclei in lithium vapour at room temperature do not combine to form a carbon nucleus because:

Which of the following is a fusion reaction?

Assertion :  In Young’s double slit experiment, the fringes become indistinct if one of the slits is covered with cellophane paper.
Reason     : The cellophane paper decrease the wavelength of light.(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.

The vertical component of earth's magnetic field is zero at or The earth's magnetic field always has a vertical component except at the(a) Magnetic poles(b) Geographical poles(c) Every place(d) Magnetic equator

Two identical p-ri junctions may be connected in series with a battery in three ways (figure). The potential difference across the two p-n. junctions are equal in:

1. Circuit 1 and circuit 2.
2. Circuit 2 and circuit 3.
3. Circuit 3 and circuit 1.
4. Circuit 1 only.