1
AIPMT 2015
MCQ (Single Correct Answer)
+4
-1
Change Language
A force $$\overrightarrow F = \alpha \widehat i + 3\widehat j + 6\widehat k$$ is acting at a point $$\overrightarrow r = 2\widehat i - 6\widehat j - 12\widehat k$$. The value of $$\alpha $$ for which angular momentum about origin is conserved is
A
zero
B
1
C
$$-$$ 1
D
2
2
AIPMT 2015
MCQ (Single Correct Answer)
+4
-1
Change Language
A satellite S is moving in an elliptical orbit around the earth. The mass of the satellite is very small compared to the mass of the earth. Then,
A
the linear momentum of S remains constant in magnitude.
B
the acceleration of S is always directed towards the centre of the earth.
C
the angular momentum of S about the centre of the earth changes in direction, but its magnitude remains constant.
D
the total mechanical energy of S varies periodically with time.
3
AIPMT 2015
MCQ (Single Correct Answer)
+4
-1
Change Language
The coefficient of performance of a refrigerator is 5. If the temperature inside freezer is $$-$$20oC, the temperature of the surroundings to which it rejects heat is
A
11oC
B
21oC
C
31oC
D
41oC
4
AIPMT 2015
MCQ (Single Correct Answer)
+4
-1
Change Language
The value of coefficient of volume expansion of glycerin is 5 $$ \times $$ 10$$-$$4 K$$-$$1. The fractional change in the density of glycerin for a rise of 40oC in its temperature, is
A
0.025
B
0.010
C
0.015
D
0.020