1
Q:

# A cup of hot coffee is placed on a metal table in a room. By which of the following methods does it lose heat?

 A) conduction and convection only B) conduction and radiation only C) convection and radiation only D) conduction, convection and radiation

Explanation:

Part of the heat is conducted away by the metal table. Convection currents in air near the surface of the coffee are set up which accounts for some heat loss. Heat is also lost by radiation from the hot coffee to the surroundings. Most of the heat is lost by the last method.

Subject: Physics
Q:

What is the full form of "RADAR" ?

 A) Radio Detecting and Ranging B) Region Device and Ranging C) Radio Detect and Rangs D) Radio Device and Ranging

Explanation:

Filed Under: Physics
Exam Prep: AIEEE , Bank Exams , CAT
Job Role: Bank Clerk , Bank PO

7 429
Q:

If a carrier wave of 1000 kHz is used to carry the signal, the length of transmitting antenna will be equal to _____ ?

 A) 300 m B) 30 m C) 3 m D) 0.3 m

Explanation:

h =   = 3 × 108/106 = 300 m

Filed Under: Physics
Exam Prep: AIEEE , Bank Exams , CAT , GATE
Job Role: Analyst , Bank Clerk

7 421
Q:

Quality of transmission depends upon

 A) Nature of signal only B) Nature of medium only C) Both (A) and (B) D) Neither A nor B

Explanation:

Quality of transmission is governed both by nature of signal and nature of communication channel/medium.

Filed Under: Physics
Exam Prep: AIEEE , Bank Exams , CAT
Job Role: Bank Clerk , Bank PO

5 389
Q:

The rate of change of linear momentum of a body falling freely under gravity is equal to it's ____ ?

 A) Kinetic Energy B) Weight C) Potential Energy D) Impulse

Explanation:

Rate of change of impulse equals the force . In case of freely falling body the only force is the weight.

Filed Under: Physics
Exam Prep: AIEEE , Bank Exams
Job Role: Bank Clerk

7 515
Q:

A disk and a sphere of same radius but different masses roll on two inclined planes of the same altitude and length. Which one of the two objects gets to the bottom of the plane first ?

 A) Depends on their masses B) Sphere C) Disk D) Both reach at the same time

Explanation:

Time does not depend on mass, else

$\inline \fn_jvn T \prec \sqrt{\left ( 1 +\frac{k^{2}}{R^{2}} \right )}$

$\inline \fn_jvn \frac{k^{2}}{R^{2}}$  => is least for 'sphere' and

hence least time is taken by sphere.