Given instructions same as in chapter 1.
Assertion:In Hertz experiment, the electric vector of radiation produced by a source gap is parallel to the gap.
Reason:Production of sparks between the detector gap is maximum when it is perpendicular to the source gap.

Given instructions same as in chapter 1. Assertion:Ultraviolet radiations are of higher frequency waves are dangerous to human beings. Reason:Ultraviolet radiations are absorbed by the atmosphere.

Given instructions same as in chapter 1. Assertion: Any substance can be used for the emission of photoelectrons. Reason: Radiations of suitalbe frequency (more than threshold frequency) should be available.

General instruction same as in chapter 1. Assertion: The electrostatic force between the plates of a charged isolated capacitro increases, when a dielectric fills whole space between the plates. Reason:The electric field between the plates of a charged isolated capacitor increases, when a dielectric fills the whole space between the plates.

Given instructions same as in chapter 1. Assertion: For photoelectric effect to take place, the frequency of incident of incident radiations should be more than threshold frequency of a given metal Reason: 1/2 mv^2=h(v-v_0) .

General instruction same as in chapter 1. Assertion: No interference pattern is detected when two coherent sources are infinitely close to each other. Reason:The Fringe width is inversly proportional to the distance between the two slits and a singel fringe may occupy the whole screen.

In these question, a statement of assertion followed by a statement of reason is given .Choose the correct answer out of the following choices: Assertion and reason both are correct statements and reason is correct explanation for assertion. Assertion and reason both are correct statements but reason is not correct explanation for assertion. Assertion is correct statement but reason is wrong statement. Assertion is wrong statement but reason is correct statement. Assertion: The displacement current goes through the gap between the plates of the capacitor ,when the charge of the capacitor does not change. Reason: The displacement current arises in the region in which the electric field and hence the electric flux does not change with the time.

The question given below consist of an assertion (A) and a reason ( R). Use the following key to choose the appropriate answer to these questions from the codes (a), (b), ( c) and (d) given below: (a) Both A and R are true and R is the correct explanation of A. (b) Both A and R are true but R is NOT the correct explanation of A. (c) A is true but R is false. (d) A is false and R is also false. Assertion: The energy gap between the valence band and conduction band is greater in silicon than germanium. Reason: Thermal energy produces fewer minority carries in silicon than in germanium.

Each question contains STATEMENTS-1 (Assertion) and STATEMENT -2 (Reason). Examine the statements carefully and mark the correct answer according to the instructions given below: STATEMENT-1: Product is formed only when the required orientation and energy conditions are met. STATEMENT-2: All collisions between reactants yield the desired product a) If both the statements are TRUE and STATEMENT-2 is the correct explanation of STATEMENT-1 b) If both the statements are TRUE and STATEMENT-2 is NOT the correct explanation of STATEMENT-1 c) If STATEMENT-1 is TRUE and STATEMENT-2 is FALSE d) If STATEMENT-1 is FALSE and STATEMENT-2 is TRUE

In figure S is a monochromatic point source emitting light of wavelength lambda=500 nm. A thin lens of circular shape and focal length 0.10 m is cut into two identical halves L_(1) and L_(2) by a plane passing through a doameter. The two halves are placed symmetrically about the central axis SO with a gap of 0.5 mm. The distance along the axis from A to L_(1) and L_(2) is 0.15 m , while that from L_(1) and L_(2) to O is 1.30 m. The screen at O is normal to SO. (b) If the gap between L_(1) and L_(2) is reduced from its original value of 0.5 mm, will the distance OP increases, devreases or remain the same?

In figure S is a monochromatic point source emitting light of wavelength lambda=500 nm. A thin lens of circular shape and focal length 0.10 m is cut into two identical halves L_(1) and L_(2) by a plane passing through a doameter. The two halves are placed symmetrically about the central axis SO with a gap of 0.5 mm. The distance along the axis from A to L_(1) and L_(2) is 0.15 m , while that from L_(1) and L_(2) to O is 1.30 m. The screen at O is normal to SO. (a) If the 3^(rd) intensity maximum occurs at point P on screen, find distance OP.