Physics - Online Test
Q1. If a charge moves in an electrical field
Answer : Option C
Explaination / Solution:
Ambiguous question. Energy may be gained or lost depending on the sign of the charge and the electric field. It can also remain unchanged if the charge moves perpendicular to the direction of the field.
Q2. The specific gravity of a material is
Answer : Option C
Explaination / Solution:
The specific gravity of an object is the ratio between the density of an object to a reference liquid. Usually, this reference liquid is water, which has a density of 1 g/mL or 1 g/cm3.
Water has a specific gravity equal to 1. Materials with a specific gravity less than 1 are less dense than water, and will float on the pure liquid; substances with a specific gravity more than 1 are more dense than water, and will sink.
Q3. Kinetic theory relates measurable properties.
Answer : Option D
Explaination / Solution:
Kinetic theory explains the behaviour of gases based on the idea that the gas consists of rapidly moving atoms or molecules. It also relates measurable properties of gases such as viscosity, conduction and diffusion with molecular parameters, yielding estimates of molecular sizes and masses.
Q4. Atomic mass unit (u) is defined as ________ of the mass of the carbon () atom.
Answer : Option B
Explaination / Solution:
For standardization, a specific atomic nucleus (carbon-12) had to be chosen because the average mass of a nucleon depends on the count of the nucleons in the atomic nucleus due to mass defect. This is also why the mass of a proton or neutron by itself is more than (and not equal to) 1 u.
Q5. According to Cartesian sign convention the heights measured
Answer : Option D
Explaination / Solution:
No Explaination.
Q6. which of the following best describes the difference between electric and magnetic fields
Answer : Option B
Explaination / Solution:
The electrostatic force experienced by a positive charge q placed in an electric field is . The force acts in the direction of the electric field.The magnetic force acting on a charge of magnitude q moving with a velocity 'v' is .This acts in a direction perpendicular to the plane containing the vectors. and
Q7.
The ice and steam point have values 32 F and 212 F respectively, on the Fahrenheit scale. Corresponding values on the Centigrade scale are
Answer : Option D
Explaination / Solution:
C5=F−329
Q8. Fundamental or base quantities are arbitrary. In SI system these are
Answer : Option A
Explaination / Solution:
A base quantity is chosen and arbitrarily defined, rather than being derived from a combination of other physical quantities. The 7 base quantities are:
| PHYSICAL QUANTITY | BASE SI UNIT |
|---|---|
| Mass (m) | Kilogram (Kg) |
| Length (ll) | Metre (m) |
| Time (t) | Second (s) |
| Current (II) | Ampere (A) |
| Temperature (T) | Kelvin (K) |
| Amount of sub. (n) | Molar (mol) |
| Luminous Intensity (L) | Candela (cd |
Q9. The instrument for the accurate measurement of the e.m.f of a cell is
Answer : Option D
Explaination / Solution:
Both potentiometer and voltmeter are devices to measure potential difference. E M F is the terminal p.d between the electrodes of a cell in open circuit, i.e., when no current is drawn from it. Potentiometer measures the potential difference using null deflection method, where no current is drawn from the cell; whereas voltmeter needs a small current to show deflection. So, accurate measurement of p.d is done using a potentiometer.
Q10. How can you describe a periodic motion
Answer : Option D
Explaination / Solution:
A motion of a body that repeats itself at regular intervals of time on the same path like rotation of earth around sun in 365.25 days
