RRB JE GK Questions 2026

A dollar sign locks the part of the address that follows it, so $A$1 has both the column and the row locked and keeps pointing at cell A1 however far the formula is copied.

Excel treats whatever follows an equals sign as something to be calculated, so =A1+B1 adds the two cells and =SUM(A1:A10) totals a range.

From Excel 2007 the grid of one worksheet was enlarged to 1,048,576 rows and 16,384 columns, so the very last cell of the sheet is XFD1048576.

From Excel 2007 onwards the suite moved to the Office Open XML formats, and a plain workbook saves with the.xlsx extension.

Ctrl together with F2 opens the print area of the Backstage view in Excel, Word and PowerPoint, where the page is shown exactly as it will be printed and the printer, copies, orientation and margins can be set.

An electronic spreadsheet stores data in a grid of rows and columns and recalculates its formulas whenever a value changes, and Excel is the spreadsheet program of the Microsoft Office suite.

LEN returns the number of characters in an entry, counting letters, digits, punctuation and spaces alike, so =LEN("Excel") gives 5.

The title bar is the strip along the very top of the Excel window, and it carries the name of the open workbook followed by the name of the program, for example Book1 - Excel.

Pressing Shift together with the spacebar selects the whole row that holds the active cell, from column A right across to the last column of the grid.

The sensation of a sound persists in the human brain for roughly one tenth of a second, so a reflected sound must arrive at least that much after the original to be heard as a separate echo.

SONAR stands for Sound Navigation and Ranging. A transmitter on the ship sends short ultrasonic pulses into the water, the pulses are reflected from the sea bed, a submarine, an iceberg or a shoal of fish, and a detector records the returning echo.

Sound travels fastest in solids because their particles are packed closely and are strongly bound, so a disturbance is passed on to the next particle almost at once.

This is the band of frequencies to which a healthy human ear responds, and the upper limit falls with age.

A vacuum contains no particles, and a mechanical wave such as sound can travel only by making particles vibrate and hand the disturbance on to their neighbours.

In a sound wave the particles of the medium vibrate back and forth along the same line in which the wave is travelling, producing regions where they crowd together, called compressions, and regions where they spread apart, called rarefactions.

The flash and the clap are produced at the same instant by the same discharge.

Amplitude is the maximum displacement of a particle of the medium from its rest position, and the energy carried by a wave increases with the square of the amplitude.

Convert the units first: 1 kilohertz is 1000 hertz and 50 centimetres is 0.5 metre. The speed is frequency multiplied by wavelength, that is 1000 multiplied by 0.5, which gives 500 metres per second.

Pitch is the characteristic of a sound by which the brain judges it as shrill or flat, and it is decided by the frequency of the wave.

The speed of a wave is the product of its frequency and its wavelength, so the speed here is 50 hertz multiplied by 4 metres, that is 200 metres per second.