NTSE SAT Physics Papers 12

This is NTSE SAT Physics Papers 12 .. There are 15 questions in this test with each question having around four answer choices.

Questions & Answers

A ship sends a sonar wave to the sea bed which is flat and measured several times over a large area, One day the reflected sound wave takes longer time than in previous measurements. The possible reason is:

A
there is a solid object of large size in the path of sonar wave.
B
the loudness of the sonar wave, generated by the equipment is lower than previous measurement.
C
the frequency of the sonar wave, generated by the equipment is lower than previous measurements.
D
there is a huge air bubble in the path of sonar wave.
Correct

Which of the following ray diagram is correct?

A
B
C
Correct
D

A concave lens always gives a virtual image. In optical lenses worn by humans which of the following statements is true?

A
The lens can never be concave.
B
In some cases the lens can be concave if the focal length is much larger than 2.5 cm
Correct
C
All focal length concave lenses are possible
D
All focal length convex lenses are possible

A geo-stationary satellite is orbiting around earth at height of 30,000 km in circular orbit. The radius of the earth is taken as 6000 km. The geo-stationary satellite comes back to its position after one revolution in exactly 24 hours. Let the acceleration due to gravity (g) be 10 and mass of satellite be 1000 kg; calculate the work done in 12 hours when moving under gravitational force.

A
\({\text{1}}{\text{.8}}\pi {\text{ \times 1}}{{\text{0}}^{14}}{\text{J }}\)
B
\({\text{2}}\pi \,{\text{ \times 7}}{\text{.2}}\pi {\text{ \times 1}}{{\text{0}}^{14}}{\text{J }}\)
C
\({\text{3}}{\text{.6}}\pi {\text{ \times 1}}{{\text{0}}^{14}}{\text{J }}\)
D
0 Joule
Correct

Consider a simple circuit containing a battery and three identical incandescent bulbs A, B and C. Bulb A is wired in parallel with bulb B and this combination is wired in series with bulb C. What would happen to the brightness of the other two bulbs if bulb A were to burn out?

A
Bulb B would get brighter and bulb C would get dimmer
Correct
B
Both A and B would get brighter
C
There would be no change in the brightness of either bulb B or bulb C
D
Only bulb B would get brighter

Three different circuits (I. II and III) are constructed using identical batteries and resistors of R and 2R ohm. What can be said about current I in arm AB of each circuit?

A
\({{\text{I}}_I}{\text{ = }}{{\text{I}}_{II}}{\text{ = }}{{\text{I}}_{III}}\)
Correct
B
\({\text{ }}{{\text{I}}_I}{\text{ < }}{{\text{I}}_{II}}{\text{ < }}{{\text{I}}_{III}}\)
C
\({{\text{I}}_{II}}{\text{ < }}{{\text{I}}_I}{\text{ < }}{{\text{I}}_{III}}\)
D
\({{\text{I}}_I}{\text{ > }}{{\text{I}}_{II}}{\text{ = }}{{\text{I}}_{III}}\)

A uranium nucleus at rest decays into a thorium nucleus and a helium nucleus, as shown below. Which of the following is true? \({}_{92}^{235}U \to {}_{90}^{231}Th + {}_2^4He\)

A
The helium nucleus has more kinetic energy than the thorium nucleus
Correct
B
Each decay product has the same kinetic energy
C
The decay products tend to go in the same direction
D
The thorium nucleus has more momentum than the helium nucleus

The figure below shows the position of a ball at t = 0, t = 1s, t = 2s, t = 3s and t = 4s : Which of the graph below is a possible graph of the position x(t)?

A
B
Correct
C
D

The graph shows position as a function of time for two trains A and B running on parallel tracks. For times greater than t = 0, which of the following statement is true?

A
At time \({{\text{t}}_B}\), both trains have the same velocity
B
Both trains may have the same velocity at some time earlier than \({{\text{t}}_B}\).
Correct
C
Graph indicates that both trains have the same acceleration at a given time
D
Both trains speed up all the time

The figure shown below depicts the distance travelled by a body as a function of time. The average speed and maximum speed between 0 and 20 s are:

A
1 m/s, 1.6 m/s respectively
B
2.0 m/s, 2.6 m/s respectively
C
1 m/s, 2.0 m/s respectively
Correct
D
1.3 m/s, 2.0 m/s respectively

A hypothetical planet has density \(\rho \).radius R. and surface gravitational acceleration g. If the radius of the planet were doubled, but the planetary density stayed the same, the acceleration due to gravity at the planet’s surface would be:

A
g/2
B
2 g
Correct
C
G
D
4 g

Three rings P, Q and R are dropped at the same time over identical hollow magnets as shown below: Which of the following describes the order in which the ring P, Q and R reach the bottom of the magnet?

A
They arrive in the order P, Q, R
B
Rings Q and R arrive simultaneously, followed by P
C
They arrive in the order, P, Q, R
D
Rings P and R arrive simultaneously, followed by Q
Correct

An electron moving with uniform velocity in x direction enters a region of uniform magnetic field along y direction. Which of the following physical quantity(ies) is (are) non-zero and remain constant? A. Velocity of the electron B. Magnitude of the momentum of the electron C. Force on the electron D. The kinetic energy of electron

A
Only I and II
B
Only III and IV
C
All four
D
Only II and IV
Correct

A car is moving with a constant speed of 70 km/h. Which of the following statements is correct?

A
The car has an acceleration only if it is moving along a curved path
Correct
B
The car may not have an acceleration even if it is moving along a curved path
C
The car may have an acceleration even if it is moving along a straight path
D
The acceleration of the car is definitely zero

A box of mass 20 kg is pushed along a rough floor with a velocity 2 m/s and then let go. The box moves 5 m on the floor before coming to rest. What must be the frictional force acting on the box?

A
4 N
B
2 N
C
8 N
Correct
D
20 N