Kinematics
momentum
Waves and sound
optics
Electricity and magnetism
100
From the top of a tower of height 50m, a ball is thrown vertically upwards with a certain velocity. It hits the ground 10 s after it is thrown up. How much time does it take to cover a distance where and are two points 20m and 40m below the edge of the tower?
0.4 s
100
What is the SI unit for momentum?
kg·m/s
100
What is the wavelength of a sound wave with a frequency of 430 Hz?
The wavelength of the sound wave is approximately
0.798 m
.
100
The rainbow which forms when a light ray undergoes two total internal reflections inside a raindrop, is termed as:
Secondary rainbow
100
How could you increase the strength of an electromagnet?
A:increase the number of turns in the coil of wire
B:use more current
C: use a larger bar
D:All of the above
D: All of the above
200
A stone is thrown vertically upwards with kinetic energy K. The kinetic energy at the highest point is
Zero
200
An object's momentum is calculated by multiplying its
mass and velocity.
200
What is the wavelength of an ultrasonic wave with a frequency of 35 kHz?
The wavelength of the ultrasonic wave is
9.8×10-3
200
The letters which appear minimum raised if a piece of plane glass is placed on a word with letters of different colours is
Red
200
In a recycling plant, how can an electromagnet be used to sort iron cans from aluminum cans?
A:By changing the color of the aluminum cans with the electromagnet
B:By repelling the aluminum cans with the electromagnet
C:By attracting the iron cans with the electromagnet
D:By heating the iron cans with the electromagnet
C:By attracting the iron cans with the electromagnet
300
A train crosses a platform 100 m long in 60 seconds at a speed of 45 km / hr. The time taken by the train to cross an electric pole is:
52 sec
300
To calculate an object's momentum, you would use the formula
300
What is the wavelength of an infrasonic wave with a frequency of 15 Hz?
The wavelength of the infrasonic wave is approximately
22.87 m
.
300
A hollow lens is made of thin glass and in the shape of a double concave lens. It can be filled with air, water of refractive index 1.33 or of refractive index 1.6. It will act a diverging lens if it is
Filled with and immersed in water
300
A factory uses electromagnets to lift heavy metal objects. Which material should be used for the core of these electromagnets to ensure they can release the objects quickly?
A:Copper
B:Aluminum
C:Steel
D:Soft iron
D:Soft iron
400
For a body moving along a straight line, the following graph is obtained.
According to the graph, the displacement during
Uniform acceleration is less than that during uniform motion
400
If a body of mass 2 kg is moving with a velocity of 30 m/s, then on doubling its velocity the momentum becomes _____.
120 kgm/s
400
What is the frequency of a sound wave with a wavelength of 0.5 m?
The frequency of the sound wave is
686 Hz
.
400
A symmetric double convex lens of power 4 D is cut in two halves by a plane perpendicular to the principal axis. The power of each half is:
2 D
400
A student wants to make a strong electromagnet to lift small metal objects. Which of the following changes will help achieve this goal?
A:Use a longer wire with fewer turns
B:Use a wire with higher resistance
C:Increase the current flowing through the coil
D:Increase the distance between the electromagnet's poles
C:Increase the current flowing through the coil
500
A stone is just released from the window of a train moving along a horizontal straight track. The stone will hit the ground following a ________
parabolic path
500
A ball is moving at 4 m/s and has momentum 48 kgm/s. What is the ball's mass?
12 kg
500
What is the frequency of a sound wave with a wavelength of 1.7 m?
The frequency of the sound wave is
200 Hz
500
If two , lenses are mounted at some distance apart, the equivalent power will always be negative, if the distance is
Greater than
500
Oersted made the discovery that electric current creates a ________.
A:magnetic field
B:electromagnetic wave
C:resistor
D:battery
A:magnetic field