Assertion:  No power loss associated with pure capacitor in ac circuit.

Reason: No current is flowing in this circuit.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false

The camera lens has an aperture off and the exposure time is ( 1/60) s. What will be the new exposure time if the aperture become 1.4 f ?

• $\frac{1}{42}$

• $\frac{1}{56}$

• $\frac{1}{72}$

• $\frac{1}{31}$

A point source is kept at a distance of   1000 m has an illumination I. To change the illumination to 161 the new distance should become

• 250 m

• 500 m

• 750 m

• 800 m

If collector current is 120 mA and base current is 2 mA and resistance gain is 3, what is power again?

• 180

• 10800

• 1.8

• 18

What is the energy of He⁺ electron in first orbit?

• 40.8 eV

• -27.2 eV

• -54.4 eV

• -13.6 eV

If the highest modulating frequency of the wave is 5 kHz, the number of stations that can be accomodated in a 150 kHz bandwidth ?

• 15

• 10

• 5

• None of these

47.

Zener diode acts as a/an

• oscillator

• regulator

• rectifier

• filter

In communication with help of antenna if height is dobled then the range covered which was initially r would become

• $\sqrt{2}\mathrm{r}$

• 3r

• 4r

• 5r

In the half wave rectifier circuit operating from 50 Hz mains frequency, the fundamental frequency in the ripple would be

• 25 Hz

• 50 Hz

• 70.7 Hz

• 100 Hz

What is the amount of energy released by deuterium and tritium fusion?  [ Given: ${\mathrm{M}}_{{}_1{}^2\mathrm{H}}$ =2.0141024 u,  ${\mathrm{M}}_{{}_1{}^3\mathrm{H}}$ = 3.0160504 ,  ${\mathrm{M}}_{{}_0{}^1\mathrm{n}}$ = 1.0086654 u ]

• 60.6 eV

• 12.6 eV

• 17.6 eV

• 28.3 eV