1 ) An astronaut in
space comes to know of an explosion on a near
planet . So the astronaut came to know about this explosion because of .
. . . . . . . . . ,
A ) light , B
) sound ,
C ) both of these , D ) None
of these ,
Correct Answer :
- A ) light ,
Because in space
light travels but sound does not travels , so he saw the explosion as a light .
2 ) The unit of focal
length of Lens is . . . . . . . . . . ,
A ) diopter , B
) seimen ,
C ) hertz , D
) None of these ,
Correct Answer :
- A ) diopter ,
3 ) Temperature coefficient of resistance : -
4 ) A ( 100 W , 200 V
) bulb is connected to a 160 V power supply . The power consumption would be :
-
A ) 42 W , B
) 64 W ,
C ) 92 W , D
) None of these ,
Correct Answer :
- B ) 64 W ,
Solution : -
5 ) A 50 volt battery
is connected across 10 ohm resistor . The current is 4.5 A . The internal
resistance of battery is : -
A ) 1.1 ohm , B
) 3.8 ohm ,
C ) 4.1 ohm , D
) None of these ,
Correct Answer :
- A ) 1.1 ohm ,
Solution : -
We have a formula : -
I =
V / ( R + r )
,
So , ( R + r )
= V / I ,
So , r = ( V / I ) – R ,
r = ( 50
/ 4.5 ) – 10 ,
r =
1.1 ohm ,
Answer .
OR
6 )
Five resistances have
been connected as shown in figure . The effective resistance between A and B
is : -
A ) 14 / 3 , B
) 19 / 2 ,
C ) 23 , D
) None of these ,
Correct Answer :
- A ) 14 / 3 ,
Solution : -
7 )
Seven resistances are
connected as shown in figure . The equivalent resistance between A and B is : -
A ) 1 Ω , B
) 4 Ω ,
C ) 11 Ω , D
) None of these ,
Correct Answer :
- B ) 4 Ω ,
Solution : -
8 ) The number of
neutrons in parent nucleus which gives N¹⁴
on beta emission is : -
A ) 7 , B
) 8 ,
C ) 9 , D
) None of these ,
Correct Answer :
- B ) 8 ,
Solution : -
6C¹⁴ ----------->
7N¹⁴ + -1e.
So no. of neutrons in
parent nucleus is : - 14 - 6 = 8 .
