MUET Entry Test - Page 3 of 10

The charge which is used to produce an electric field is called

A. Electric field
B. Field Charge
C. Electric intensity
D. Test Charge

Answer

D. Test Charge

The charge responsible for creating an electric field is called a D. Test Charge (although this terminology is not the most common).

Here’s a breakdown of the terms:

Electric Field: This describes the region of influence around a charged object where other charged objects experience a force. It’s not a physical entity itself, but rather a concept to describe the effect of the charge.
Field Charge: This term isn’t typically used in standard physics vocabulary.
Electric Intensity: This is another term for electric field, but it emphasizes the strength of the field at a specific point.
Test Charge: This is a hypothetical charged particle that is used to probe an electric field. By observing the force exerted on the test charge, we can determine the strength and direction of the electric field at that point.

However, it’s more common to simply refer to the charged object itself as the source of the electric field. For example, we might say “the positive charge creates an electric field.”

The charge which is used to produce an electric field is called Read More »

The average velocity gained by the electron in a conductor placed in an electric field is called

A. Variable Velocity
B. Phase Velocity
C. Drift Velocity
D. Instantaneous Velocity

Answer

C. Drift Velocity

The average velocity gained by the electron in a conductor placed in an electric field is called:

C. Drift Velocity

Here’s why:

Electrons in a conductor constantly move around due to their thermal energy.
When an electric field is applied, these electrons experience a force that causes them to accelerate in the direction opposite the electric field.
However, they also collide with ions (positively charged atoms) in the conductor, which disrupts their straight-line motion.

Drift velocity refers to the average velocity that electrons acquire due to the applied electric field, considering both the acceleration caused by the field and the collisions with ions. It’s a net effect that represents the overall movement of electrons in the conductor.

The other options are not as accurate in this context:

A. Variable Velocity: While the electrons’ instantaneous velocity does vary due to collisions, drift velocity refers to the average of these variations.
B. Phase Velocity: Phase velocity describes the propagation speed of a wave, not the average velocity of electrons in a conductor.
D. Instantaneous Velocity: This refers to the electron’s velocity at a specific moment, which constantly changes due to collisions. Drift velocity considers the average of these instantaneous velocities.

The average velocity gained by the electron in a conductor placed in an electric field is called Read More »

A transformer is used to

A. Transform alternating current voltage alternating
B. Convert Direct Current into Alternating Current
C. Convert Alternating Current into Direct Current into Electrical
D. Convert Mechanical energy

Answer

A. Transform alternating current voltage alternating

The primary function of a transformer is to:

A. Transform alternating current voltage (AC)

While transformers can’t directly convert AC to DC (option B) or vice versa (option C), they can definitely change the voltage level of an AC current. They can either increase the voltage (step-up transformer) or decrease the voltage (step-down transformer). This is crucial for efficient transmission and distribution of electrical power.

Option D (convert mechanical energy) is not the main function of a transformer. While transformers have coils with magnetic fields that can interact with some mechanical devices, their core purpose is to manipulate AC voltage.

A transformer is used to Read More »

A Wheatstone bridge is most sensitive when

A. The ratio arm is equal to one
B. The ratio arm is equal to ten
C. Any value
D. Both a and b are true

Answer

A. The ratio arm is equal to one

In a Wheatstone bridge, the sensitivity refers to how easily you can detect a change in the unknown resistance. For maximum sensitivity, a specific condition on the ratio arms is required:

A. The ratio arm (one of the known resistances) is close in value to the unknown resistance.

Here’s why:

The Wheatstone bridge works by balancing the potential difference across a galvanometer.
When all resistors have similar values, even a small change in the unknown resistance will cause a more significant deflection in the galvanometer compared to a situation where the ratio arm is much larger or smaller than the unknown resistance.

So, option A is the most accurate statement.

Here’s why the other options are not quite true:

B. The ratio arm is equal to ten: While having the ratio arm close in value is important, an exact match of 10 isn’t necessary. It should be in the same order of magnitude as the unknown resistance for optimal sensitivity.
C. Any value: Not any value will provide maximum sensitivity. As explained above, a ratio arm close to the unknown resistance is crucial.
D. Both a and b are true: While option A captures the essence of sensitivity, option B is not entirely accurate as mentioned above.

A Wheatstone bridge is most sensitive when Read More »

The electromagnetic waves travel in free space with speed of _______

A. Light
B. Sound
C. Jet
D. None of these

Answer

A. Light

The electromagnetic waves travel in free space with a speed of:

A. Light

More specifically, the speed of electromagnetic waves in free space is approximately:

3 x 10^8 meters per second (m/s)
Often written as “c”

This speed is a fundamental constant in physics and is known as the speed of light.

The other options are not correct:

B. Sound: Sound travels much slower than light, typically around 343 m/s in dry air at room temperature.
C. Jet: The speed of a jet airplane is much slower than the speed of light and depends on the specific jet’s design and operating conditions.

The electromagnetic waves travel in free space with speed of _______ Read More »

The distance between the two consecutive nodes or anti-nodes is the same or equal to

A. Half of the wavelength
B. Double of the wavelength
C. Full the wavelength
D. Three times the wavelength

Answer

A. Half of the wavelength (λ/2)

The distance between two consecutive nodes or anti-nodes in a standing wave is:

A. Half of the wavelength (λ/2)

Here’s why:

A node is a point in a standing wave where the medium experiences minimal displacement (movement).
An antinode is a point where the medium experiences maximum displacement.
In a standing wave, these points alternate regularly.

The distance between a node and the next anti-node (or vice versa) is exactly half the wavelength (λ/2). This is because one full cycle of the wave (from peak to trough and back to peak) corresponds to the wavelength.

The other options are not correct:

B. Double of the wavelength: This would be the distance between two consecutive antinodes, which is a full wavelength (λ).
C. Full wavelength: This is the distance between two consecutive peaks (antinodes).
D. Three times the wavelength: This is not a typical distance between nodes or antinodes in a standing wave.

The distance between the two consecutive nodes or anti-nodes is the same or equal to Read More »

The body is said to be in equilibrium if all the forces and torques will become equal to

A. One
B. Zero
C. Four
D. Six

Answer

B. Zero

The correct answer is:

B. Zero

A body is considered to be in equilibrium if the sum of all the forces and torques acting on it is equal to zero. This means there’s no net force or net torque causing the body to accelerate or rotate.

Here’s why the other options are incorrect:

A. One: The forces and torques don’t necessarily all have to be the same magnitude or direction. As long as they add up to zero vectorially (net force and torque are zero), the body is in equilibrium.
C. Four or D. Six: These numbers might be specific requirements for certain equilibrium situations involving multiple forces/torques acting in different planes, but in general equilibrium simply requires the net force and net torque to be zero.

The body is said to be in equilibrium if all the forces and torques will become equal to Read More »

The field is said to be conservative if the work done along a closed path is

A. Zero
B. Negative
C. Positive
D. Infinity

Answer

A. Zero

The correct answer is:

A. Zero

A field is considered conservative if the work done moving along any closed path (a path that starts and ends at the same point) depends only on the starting and ending points, and not on the specific path taken between those points. In other words, the work done for a round trip in a conservative field is zero.

Here’s why the other options are incorrect:

B. Negative: The work done can be positive or negative depending on the specific force and path, but in a conservative field, a closed path will always result in zero net work done.
C. Positive: Similar to negative, the work done can be positive, but for a closed path in a conservative field, it will always sum up to zero.
D. Infinity: The work done wouldn’t necessarily be infinite. It depends on the specific force and path. In a conservative field for a closed path, it will always be zero.

The field is said to be conservative if the work done along a closed path is Read More »

A satellite remains in an orbit around the earth due to the centripetal force provided by

A. Gravitational Pull of the sun on the satellite.
B. Gravitational Pull of earth on the satellite
C. The rocket engine attached to the satellite
D. None of the above

Answer

B. Gravitational Pull of earth on the satellite

The correct answer is:

B. Gravitational Pull of earth on the satellite

Here’s why:

A satellite orbits Earth in a (nearly) circular path.
To maintain a circular path, an object needs a centripetal force acting inwards, constantly “pulling” it towards the center of the circle.
Earth’s gravity acts on the satellite, pulling it inwards.
This inward pull from Earth’s gravity provides the necessary centripetal force that keeps the satellite in its orbit.

The other options are not responsible for a satellite’s orbit around Earth:

A. Gravitational Pull of the sun on the satellite: The Sun’s gravity does exert a pull on the satellite, but its influence is much weaker compared to Earth’s gravity at that distance.
C. The rocket engine attached to the satellite: Rocket engines are typically used to launch the satellite into orbit, not to maintain its orbit. Once in orbit, the engine is usually turned off.

A satellite remains in an orbit around the earth due to the centripetal force provided by Read More »

When a body is thrown upward making angle of “θ” with horizontal and moves freely under the action of gravity, it is called a ______

A. Horizontal
B. Vertical
C. Projectile
D. None of these

Answer

C. Projectile

The correct answer is:

C. Projectile

When a body is thrown upwards at an angle with the horizontal and is only acted upon by gravity, it’s undergoing projectile motion.

Here’s why the other options are not correct:

Horizontal: This would describe motion purely along the horizontal plane, not involving an upward throw.
Vertical: This would describe motion purely along the vertical plane, either upwards or downwards. Projectile motion involves both horizontal and vertical components.
None of these: While there might be more specific terms for certain projectile motion scenarios, “projectile motion” is the general term used for this type of situation.

When a body is thrown upward making angle of “θ” with horizontal and moves freely under the action of gravity, it is called a ______ Read More »