1.
What type of core does a temporary electromagnet contain?
Correct Answer
B. Soft iron core
Explanation
A temporary electromagnet contains a soft iron core. Soft iron is commonly used as a core material in electromagnets because it has high magnetic permeability, meaning it can easily magnetize and demagnetize. When an electric current flows through the coil of wire surrounding the soft iron core, it creates a magnetic field. The soft iron core helps to concentrate and strengthen this magnetic field, making the electromagnet more powerful. Once the current is turned off, the soft iron core loses its magnetism, hence why it is called a temporary electromagnet.
2.
Upto what decimal place does a vernier calliper count the reading?
Correct Answer
A. Upto two decimal places
Explanation
A vernier caliper is a measuring instrument that is used to measure linear dimensions with high accuracy. It consists of a main scale and a sliding vernier scale. The main scale typically has markings up to one decimal place, while the vernier scale allows for more precise readings. In this case, the correct answer is "up to two decimal places" because the vernier scale provides an additional digit of accuracy beyond the main scale.
3.
What is the specific heat capacity of water?
Correct Answer
B. 4200 kg\J degree C
Explanation
The specific heat capacity of a substance is the amount of heat energy required to raise the temperature of a unit mass of the substance by one degree Celsius. In the case of water, the specific heat capacity is 4200 kg/J degree C. This means that it takes 4200 joules of energy to raise the temperature of 1 kilogram of water by 1 degree Celsius.
4.
What is the formula for the calculation of time period?
Correct Answer
C. T=1\f
Explanation
The correct answer is t=1\f. This formula represents the calculation of time period. The "t" represents the time period, and the "1" in the numerator indicates that it is a constant value. The "\f" in the denominator represents the frequency, which is the number of cycles or oscillations per unit of time. Dividing 1 by the frequency gives us the time period.
5.
What is the relation between one calorie and joules
Correct Answer
A. 1 C= 4.186 Joules
Explanation
One calorie is equivalent to 4.186 joules. This means that if we have 1 calorie of energy, it can also be expressed as 4.186 joules of energy.
6.
What is a positive ion known as?
Correct Answer
A. Cation
Explanation
A positive ion is known as a cation. Cations are formed when an atom loses one or more electrons, resulting in a net positive charge. They are attracted to the cathode in an electrolytic cell and are typically smaller in size compared to their parent atoms. Cations play a crucial role in various chemical reactions and are often involved in the formation of ionic compounds.
7.
Scalar quantities have __________________ but no ________________
Correct Answer
magnitude, direction
Explanation
Scalar quantities have magnitude but no direction. Scalar quantities are physical quantities that can be completely described by their magnitude or numerical value alone. They do not have any associated direction. Examples of scalar quantities include mass, temperature, time, and speed.
8.
Displacement can be zero even if the distance is not 0?
Correct Answer
A. True
Explanation
Displacement is a vector quantity that refers to the change in position of an object. It takes into account both the distance traveled and the direction of the movement. Therefore, it is possible for the distance traveled to be nonzero while the displacement is zero. This can occur when an object moves in a closed loop or returns to its original position. In such cases, the total distance traveled may be nonzero, but since the starting and ending positions are the same, the displacement is zero.
9.
If more current is applied to a solenoid then
Correct Answer
A. Its magnetic field increases
Explanation
When more current is applied to a solenoid, the magnetic field increases. This is because the magnetic field produced by a solenoid is directly proportional to the current passing through it. As the current increases, more magnetic field lines are generated, resulting in a stronger magnetic field. Therefore, the correct answer is that the solenoid's magnetic field increases.