Physics - Online Test
Q1. In a series LCR circuit supplied with AC
Answer : Option D
Explaination / Solution:
In series circuits, the current always remains same while potential is different across different circuit components
Q2. The unit of potential difference as used in electrical circuits is
Answer : Option D
Explaination / Solution:
Volt is the unit of potential difference.
Q3. According to Pascal’s law for transmission of fluid pressure external pressure applied on any part of a fluid contained in a vessel is ___________________ in all directions
Answer : Option A
Explaination / Solution:
Pascal's principle is defined as a change in pressure at any point in an enclosed fluid at rest is transmitted undiminished to all points in the fluid.
This principle is stated mathematically as:
is the hydrostatic pressure (given in pascals in the SI system), or the difference in pressure at two points within a fluid column, due to the weight of the fluid.
Q4. In dynamic equilibrium, molecules collide and change their speeds during the collision
Answer : Option C
Explaination / Solution:
All collisions between molecules among themselves or between molecules and the walls are elastic. So that total kinetic energy and total momentum is conserved. Also the average properties of gas are remains constant.
Q5. Total internal reflection can take place only if light is travelling from
Answer : Option C
Explaination / Solution:
No Explaination.
Q6. The nuclei of isotopes of a given element differ from each other in their number of
Answer : Option B
Explaination / Solution:
Isotopes are variants of a particular chemical element which differ in neutron number. All isotopes of a given element have the same number of protons in each atom.
Q7. Consider the motion of a charged particle in a uniform magnetic field directed into the paper.If velocity v of the particle is in the plane of the paper the charged particle will
Answer : Option B
Explaination / Solution:
The charged particle experiences magnetic Lorentz force given by.This force acts in the plane of the paper perpendicular to the velocity vector at all points on the plane. Magnetic Lorentz force acts like a centripetal force, causing the particle to move in a circle.
Q8. If the substance is in the form of a long rod, then for small change in temperature, ΔT, the fractional change in length, Δl/l, is
Answer : Option C
Explaination / Solution:
α=Δll×ΔTΔll=aΔT
Q9. The least count of any measuring equipment is
Answer : Option B
Explaination / Solution:
The smallest value that can be measured by the measuring instrument is called its least count. Measured values are good only up to this value. The least count error is the error associated with the resolution of the instrument.
Q10. In a meter bridge, when galvanometer & cell positions are interchanged
Answer : Option D
Explaination / Solution:
The battery in the circuit(1) shown is connected between A and C, while the galvanometer is connected between B and D. In the bridge balanced condition,
When the battery and the galvanometer are interchanged, the circuit takes the form (2). The circuit (2) can be re drawn as circuit (3). The ratio of the resistances in the bridge balanced condition is which is same as,
When the battery and the galvanometer are interchanged, the circuit takes the form (2). The circuit (2) can be re drawn as circuit (3). The ratio of the resistances in the bridge balanced condition is which is same as,
